0001562088-23-000052 | 10-K | XBRL Viewer

Cover Page - USD ($)	12 Months Ended
Cover Page - USD ($)	Dec. 31, 2022	Feb. 27, 2023	Jun. 30, 2022
Document Information [Line Items]
Document Type	10-K
Document Quarterly Report	true
Document Period End Date	Dec. 31, 2022
Document Transition Report	false
Entity File Number	001-40653
Entity Registrant Name	Duolingo, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	45-3055872
Entity Address, Address Line One	5900 Penn Avenue
Entity Address, City or Town	Pittsburgh
Entity Address, State or Province	PA
Entity Address, Postal Zip Code	15206
City Area Code	(412)
Local Phone Number	567-6602
Title of 12(b) Security	Class A common stock, $0.0001 per share
Trading Symbol	DUOL
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	false
Entity Shell Company	false
Entity Public Float			$ 1,871,523,869
Documents Incorporated by Reference	DOCUMENTS INCORPORATED BY REFERENCEPortions of the registrant’s definitive proxy statement for its 2023 annual meeting of stockholders, which the registrant intends to file pursuant to Regulation 14A with the Securities and Exchange Commission not later than 120 days after the registrant’s fiscal year ended December 31, 2022, are incorporated by reference into Part III of this Annual Report on Form 10-K.
Entity Central Index Key	0001562088
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	FY
Amendment Flag	false
Common Class A
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		32,201,681
Common Class B
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		8,434,238

Audit Information	12 Months Ended
Audit Information	Dec. 31, 2022
Audit Information [Abstract]
Auditor Name	Deloitte & Touche LLP
Auditor Location	New York, New York
Auditor Firm ID	34

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Current assets
Cash and cash equivalents	$ 608,180	$ 553,922
Accounts receivable	46,728	33,163
Deferred cost of revenues	35,041	24,219
Prepaid expenses and other current assets	7,234	7,967
Total current assets	697,183	619,271
Assets, Noncurrent
Property and equipment, net	12,969	8,211
Goodwill	4,050	0
Intangible assets, net	8,497	4,566
Operating lease right-of-use assets	22,508	28,369
Deferred tax assets	633	0
Other assets	1,507	894
Total assets	747,347	661,311
Current liabilities
Accounts payable	1,177	7,818
Deferred revenues	157,550	98,267
Income tax payable	1,069	113
Accrued expenses and other current liabilities	21,970	12,933
Total current liabilities	181,766	119,131
Liabilities, Noncurrent
Long-term obligation under operating leases	23,503	29,124
Total liabilities	205,269	148,255
Commitments and contingencies (Note 10)
Stockholders’ equity
Class A common stock, $0.0001 par value; 2,000,000 shares authorized as of December 31, 2022 and 2021; 31,899 and 16,645 issued and outstanding at December 31, 2022 and 2021, respectively Class B common stock, $0.0001 par value; 30,000 shares authorized as of December 31, 2022 and 2021; 8,462 and 21,627 issued and outstanding at December 31, 2022 and 2021, respectively	4	4
Additional paid-in capital	772,562	683,966
Accumulated deficit	(230,488)	(170,914)
Total stockholders’ equity	542,078	513,056
Total liabilities, convertible preferred stock and stockholders' equity	$ 747,347	$ 661,311

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2022	Dec. 31, 2021
Common Class A
Common stock, par value (in usd per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	2,000,000,000
Common stock, shares issued (in shares)	31,899,000	16,645,000
Common stock, shares outstanding (in shares)	31,899,000	16,645,000
Common Class B
Common stock, par value (in usd per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	30,000,000
Common stock, shares issued (in shares)	8,462,000	21,627
Common stock, shares outstanding (in shares)	8,462,000	21,627

CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Statement [Abstract]
Revenues	$ 369,495	$ 250,772	$ 161,696
Cost of revenues	99,431	69,186	45,987
Gross profit	270,064	181,586	115,709
Operating expenses:
Research and development	150,444	103,833	53,024
Sales and marketing	66,967	59,170	34,983
General and administrative	117,848	78,590	43,713
Total operating expenses	335,259	241,593	131,720
Loss from operations	(65,195)	(60,007)	(16,011)
Other income	131	318	157
Other expense	(807)	(288)	(85)
Other (expense) income, net	(676)	30	72
Loss before interest income and provision for income taxes	(65,871)	(59,977)	(15,939)
Interest income	7,235	19	231
Loss before provision for income taxes	(58,636)	(59,958)	(15,708)
Provision for income taxes	938	177	68
Net loss	(59,574)	(60,135)	$ (15,776)
Net comprehensive loss	$ (59,574)	$ (60,135)
Net loss per share attributable to Class A and Class B common stockholders, basic (in usd per share)	$ (1.51)	$ (2.57)	$ (1.24)
Net loss per share attributable to Class A and Class B common stockholders, diluted (in usd per share)	$ (1.51)	$ (2.57)	$ (1.24)

CONSOLIDATED STATEMENTS OF CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS’ EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Deficit
Convertible preferred stock beginning balance (in shares) at Dec. 31, 2019	18,247
Convertible preferred stock beginning balance at Dec. 31, 2019	$ 137,686
Increase (Decrease) in Temporary Equity [Roll Forward]
Issuance of Series G and H convertible preferred stock, net of fees (in shares)	827
Issuance of Series G and H convertible preferred stock, net of fees	$ 44,923
Convertible preferred stock ending balance (in shares) at Dec. 31, 2020	19,074
Convertible preferred stock ending balance at Dec. 31, 2020	$ 182,609
Beginning balance (in shares) at Dec. 31, 2019		12,406
Beginning balance at Dec. 31, 2019	(83,976)	$ 1	$ 11,026	$ (95,003)
Increase (Decrease) in Stockholders' Deficit [Roll Forward]
Stock-based compensation	17,031		17,031
Stock options exercised (in shares)		388
Stock options exercised	2,030		2,030
Net loss	(15,776)			(15,776)
Ending balance (in shares) at Dec. 31, 2020		12,794
Ending balance at Dec. 31, 2020	$ (80,691)	$ 1	30,087	(110,779)
Increase (Decrease) in Temporary Equity [Roll Forward]
Conversion of redeemable convertible preferred stock to common stock in connection with initial public offering (in shares)	(19,074)
Conversion of redeemable convertible preferred stock to common stock in connection with initial public offering	$ (182,609)
Convertible preferred stock ending balance (in shares) at Dec. 31, 2021	0
Convertible preferred stock ending balance at Dec. 31, 2021	$ 0
Increase (Decrease) in Stockholders' Deficit [Roll Forward]
Issuance of common stock in connection with initial public offering, net of underwriting discounts and issuance costs (in shares)		4,466
Issuance of common stock in connection with the initial public offering, net of underwriting discounts and issuance costs	426,192	$ 1	426,191
Conversion of redeemable convertible preferred stock to common stock in connection with initial public offering (in shares)		19,074
Conversion of redeemable convertible preferred stock to common stock in connection with initial public offering	182,609	$ 2	182,607
Stock-based compensation	40,804		40,804
Stock options exercised (in shares)		1,882
Stock options exercised	12,480		12,480
Common stock repurchased and retired (in shares)		(23)
Common stock repurchased and retired	(868)		(868)
Options repurchased	$ (7,335)		(7,335)
Release of restricted stock units (in shares)	79
Release of restricted stock units	$ 0
Net loss	(60,135)			(60,135)
Ending balance (in shares) at Dec. 31, 2021		38,272
Ending balance at Dec. 31, 2021	$ 513,056	$ 4	683,966	(170,914)
Convertible preferred stock ending balance (in shares) at Dec. 31, 2022	0
Convertible preferred stock ending balance at Dec. 31, 2022	$ 0
Increase (Decrease) in Stockholders' Deficit [Roll Forward]
Stock-based compensation	$ 73,820		73,820
Stock options exercised (in shares)	1,739	1,739
Stock options exercised	$ 14,776		14,776
Release of restricted stock units (in shares)		350
Release of restricted stock units	0
Net loss	(59,574)			(59,574)
Ending balance (in shares) at Dec. 31, 2022		40,361
Ending balance at Dec. 31, 2022	$ 542,078	$ 4	$ 772,562	$ (230,488)

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Cash flows from operating activities:
Net loss	$ (59,574)	$ (60,135)	$ (15,776)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	4,870	2,726	2,256
Stock-based compensation	73,820	40,804	17,031
Changes in assets and liabilities:
Deferred revenue	59,283	43,475	28,485
Accounts receivable	(13,565)	(12,713)	(10,445)
Deferred cost of revenues	(10,822)	(10,634)	(6,653)
Prepaid expenses and other current assets	(1,415)	(4,048)	(1,712)
Accounts payable	(6,655)	5,622	(1,615)
Accrued expenses and other current liabilities	8,720	3,708	6,213
Noncurrent assets and liabilities	(1,006)	365	(76)
Net cash provided by operating activities	53,656	9,170	17,708
Cash flows from investing activities:
Capitalized software expense and purchases of intangible assets	(4,562)	(2,620)	(638)
Purchase of property and equipment	(5,562)	(3,586)	(3,376)
Acquisition, net of $0 cash acquired	4,050	0	0
Net cash used for investing activities	(14,174)	(6,206)	(4,014)
Cash flows from financing activities:
Issuance of common stock in connection with the initial public offering, net of underwriting discounts and issuance costs	0	426,191	0
Net proceeds from issuance of convertible preferred stock	0	0	44,923
Proceeds from exercise of stock options	14,776	12,480	2,030
Repurchases of stock options	0	(7,335)	0
Repurchase of common stock	0	(868)	0
Net cash provided by financing activities	14,776	430,468	46,953
Net increase in cash and cash equivalents	54,258	433,432	60,647
Cash and cash equivalents - Beginning of period	553,922	120,490	59,843
Cash and cash equivalents - End of period	608,180	553,922	120,490
Supplemental disclosure of cash flow information:
Cash paid for interest	0	0	0
Cash paid for income taxes	615	132	0
Supplemental disclosure of noncash operating activities:
Implementation costs for cloud computing included in Current liabilities	0	64	0
Supplemental disclosure of noncash investing activities and financing activities:
Capitalized software and purchases of intangible assets included in Current liabilities	1,121	342	500
Property and equipment included in Current liabilities	166	230	0
Landlord incentive	$ 2,148	$ 0	$ 0

CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical)	12 Months Ended
CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical)	Dec. 31, 2022 USD ($)
Statement of Cash Flows [Abstract]
Cash acquired during acquisition	$ 0

DESCRIPTION OF THE BUSINESS AND BASIS OF PRESENTATION	12 Months Ended
DESCRIPTION OF THE BUSINESS AND BASIS OF PRESENTATION	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
DESCRIPTION OF THE BUSINESS AND BASIS OF PRESENTATION	DESCRIPTION OF THE BUSINESS AND BASIS OF PRESENTATION Duolingo, Inc. (the “Company” or “Duolingo”) was formed on August 18, 2011, and the Duolingo app was launched to the general public on June 19, 2012. The Company’s headquarters are located in Pittsburgh, Pennsylvania. On July 30, 2021, Duolingo completed its Initial Public Offering (“IPO”) of 5,872 shares of its Class A common stock at a price to the public of $102.00 per share, 4,466 of which were sold by the Company and 1,406 of which were sold by certain selling stockholders, which includes the exercise in full by the underwriters of their option to purchase from the Company an additional 766 shares of the Company’s Class A common stock. The gross proceeds to the Company from the IPO were $455,532, before deducting underwriting discounts and commissions and offering expenses payable by the Company. The Company did not receive any proceeds from the sale of shares of Class A common stock in the offering by the selling stockholders. Immediately prior to the completion of the IPO, all convertible preferred stock outstanding, totaling approximately 19,074 shares, was automatically converted into an equivalent number of shares of Class B common stock on a one-to-one basis and their carrying value of $182,609 was reclassified to additional paid-in capital within stockholders’ equity. Additionally, on July 15, 2021, 6,930 shares held by our founders were exchanged from Class A common stock into Class B common stock. Duolingo is a US-based mobile learning platform, as well as a digital language proficiency assessment exam. The Company has a freemium business model: the app and the website are accessible free of charge, although Duolingo also offers a premium service, Super Duolingo, for a subscription fee. As of the date of this filing, Duolingo offers courses in over 40 different languages, including Spanish, English, French, German, Italian, Portuguese, Japanese and Chinese. We have locations in the United States, China and Germany. Principles of Consolidation—The Consolidated Financial Statements include the accounts of the Company and subsidiaries over which the Company has control. All intercompany transactions and balances have been eliminated. Basis of Presentation—The accompanying Consolidated Financial Statements have been prepared in accordance with generally accepted accounting principles in the United States (“GAAP”) from the Company’s accounting records and reflect the consolidated financial position and results of operations for the years ended December 31, 2022, 2021 and 2020. Unless otherwise specified, all dollar amounts are referred to in thousands. The Consolidated Financial Statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”).

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

12 Months Ended

Dec. 31, 2022

Accounting Policies [Abstract]

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Accounting Principles—The Consolidated Financial Statements and accompanying notes are prepared in accordance with GAAP.

and equipment, valuation of deferred tax assets and liabilities, stock-based compensation, common stock valuation, operating lease right-of-use assets and liabilities, capitalization of internally developed software and associated useful lives and contingent liabilities. Actual results may differ materially from such estimates. Management believes that the estimates, and judgments upon which they rely, are reasonable based upon information available to them at the time that these estimates and judgments are made. To the extent that there are material differences between these estimates and actual results, the Company’s Consolidated Financial Statements will be affected.

Revenue Recognition—The Company has three predominant sources of revenue; time-based subscriptions, in-app advertising placement by third parties, and the Duolingo English Test. See Footnote 4 for further discussion.

Deferred Revenues—Revenue is recognized over the life of the subscription, or in the case of Duolingo English Test, revenue is recognized when the test is proctored. The Company classifies deferred revenue as a short-term liability on the consolidated balance sheets as the longest subscription plan is for twelve months, and Duolingo English Test purchases must be taken within 21 days.

Cost of Revenues—Cost of revenue predominantly consists of third-party payment processing fees charged by various distribution channel and hosting fees. To a much lesser extent, includes wages and stock-based compensation for certain employees in the capacity of customer support, amortization of revenue generating capitalized software, and depreciation of certain property and equipment.

Deferred Cost of Revenues—Deferred cost of revenue includes third-party payment processing fees amortized over the subscription terms in proportion to the revenue recognized. In situations where fees are charged for subscriptions that exceed one month, costs are deferred and recognized over the life of the subscription and are classified as a current asset. The Company classifies deferred cost of revenue as a short-term asset on the Company’s consolidated balance sheets as the longest subscription plan is for twelve months.

Cash and Cash Equivalents—Cash consists primarily of cash on hand and bank deposits. Cash equivalents consist primarily of money market accounts with maturities of three months or less at the date of acquisition and are stated at cost, which approximates fair value. The Company maintains cash deposits with financial institutions that may exceed federally insured limits at times. The following table shows the breakout between cash and money market funds.



	December 31, 2022		December 31, 2021
Cash	$	91,189	$	44,165
Money market funds	516,991		509,757
Total	$	608,180	$	553,922

The Money market funds are considered Level 1 financial assets. Level 1 financial assets use inputs that are the unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date.

Accounts Receivable—Accounts receivables are reported on the consolidated balance sheets at the outstanding principal amount adjusted for any allowance for credit losses and any charge offs. The Company provides an allowance for credit losses to reduce trade receivables to their estimated net realizable value equal to the amount that is expected to be collected. This allowance is estimated based on historical collection experience, the aging of receivables, specific current and expected future macro-economic and market conditions, and assessments of the current creditworthiness and economic status of customers. The Company considers a receivable delinquent if it is unpaid after the term of the related invoice has expired. Balances that are still outstanding after management has used reasonable collection

efforts are written off. The Company reviews its allowance for credit losses on a quarterly basis. As of December 31, 2022 and 2021, the Company has not recorded a reserve given the Company’s lack of historical write offs.

Property and Equipment—Property and equipment is stated at cost, less accumulated depreciation. Depreciation is computed on the straight-line method.


Asset Class			Estimated Useful Life
Furniture, fixtures and equipment			5 to 7 years
Leasehold improvements			4 to 6 years

Leasehold improvements are amortized over the lesser of the life of the lease or the estimated useful life of the leasehold improvements. Costs related to maintenance and repairs that do not extend the assets’ useful life are expensed as incurred.

Acquisition—The Company uses the acquisition method of accounting for business combination transactions, and, accordingly, recognizes the fair values of assets acquired and liabilities assumed in our Consolidated Financial Statements. Transaction costs related to the acquisition of the acquired company are expensed as incurred. The allocation of fair values may be subject to adjustment after the initial allocation for up to a one-year period as more information becomes available relative to the fair values as of the acquisition date. The Consolidated Financial Statements include the results of operations of any acquired company since the acquisition date.

Goodwill—The Company recognizes the excess of the purchase price over the fair value of identifiable net assets acquired at the acquisition date as goodwill. Goodwill is not amortized but is reviewed for impairment annually and more frequently if an event occurs or circumstances change that would more likely than not reduce the fair value of a reporting unit below its carrying value. The Company will review goodwill for impairment annually on October 1st of each fiscal year or whenever events or changes in circumstances indicate that an impairment may exist. The Company will first perform a qualitative assessment to determine whether it is more likely than not that the fair value of the reporting unit is less than its carrying value. If the reporting unit does not pass the qualitative assessment, then the reporting unit’s carrying value is compared to its fair value. If the fair value of the reporting unit is greater than the reporting unit’s carrying value, then the carrying value of the reporting unit is deemed to be recoverable. If the carrying value of the reporting unit is greater than the reporting unit’s fair value, goodwill is impaired and written down to the reporting unit’s fair value.

Intangible Assets—The majority of the Company’s intangible assets is capitalized software, with minimal other intangible assets during the years ended December 31, 2022 and 2021. The Company develops software for internal use and capitalizes the software development costs incurred during the application development stage. Costs incurred prior to and after the application development stage are charged to expense. When the software is ready for its intended use, capitalization ceases and such costs are amortized on a straight-line basis over the estimated life, which is generally three years. Relatively minor upgrades, enhancements and maintenance to the platform are expensed as incurred.

Income Taxes—The Company provides for income taxes in accordance with the asset and liability method. Under this method, deferred tax assets and liabilities are recognized for future tax consequences attributable to differences between the carrying amounts of existing assets and liabilities for financial reporting and for income tax reporting. The deferred tax asset or liability represents the future tax return consequences of those difference, which will either be taxable or deductible when the assets and liabilities are recovered or settled. A valuation allowance is established for any deferred tax asset for which it is determined that it is more likely than not that some or all of the deferred tax assets will not be

realized. The Company limits the deferred tax assets recognized related to certain officers’ compensation to amounts that it estimates will be deductible in future periods based upon Internal Revenue Code Section 162(m).

The Company utilizes a two-step approach to recognizing and measuring uncertain tax positions accounted for in accordance with the asset and liability method. The first step is to evaluate the tax position for recognition by determining whether evidence indicates that it is more likely than not that a position will be sustained if examined by a taxing authority.

The second step is to measure the tax benefit as the largest amount that is 50% likely of being realized upon settlement with a tax authority. There were no amounts recorded at December 31, 2022 and December 31, 2021 related to uncertain tax positions.

Foreign Currency—The functional currency of the Company and its subsidiaries is the United States dollar. Transactions denominated in currencies other than the functional currency are translated into the functional currency at the exchange rates prevailing at the dates of the transaction. Monetary assets and liabilities denominated in foreign currencies are translated using the exchange rate prevailing at the balance sheet date. Non-monetary assets and liabilities are translated using the historical rate on the date of the transaction. All exchange gains or losses arising from translation of these foreign currency transactions are included in net loss for the year. The Company has not, to the date of these Consolidated Financial Statements, entered into derivative instruments to offset the impact of foreign currency fluctuations.

Fair Value of Financial Instruments—The Company accounts for certain assets and liabilities at fair value in accordance with the accounting guidance applicable to fair value measurements and disclosures. The carrying values of cash, cash equivalents, accounts receivable, accounts payable, and accrued expenses are deemed to be reasonable estimates of their fair values because of their short-term nature.

Research and Development Costs—Research and development expenses are incurred as the Company maintains and enhances its software and evaluates and develops other potential applications. Such expenses include compensation of engineering, product design and testing personnel, including stock-based compensation, materials, travel and direct costs associated with the design and required testing of our platform and depreciation of certain property and equipment.

Sales and Marketing—Sales and marketing expenses are expensed as incurred and consists primarily of brand advertising, marketing, digital and social media spend, field marketing, travel, trade show sponsorships and events, conferences and other employee related compensation, including stock-based compensation for personnel engaged in sales and marketing functions, amortization of non-revenue generating capitalized software used to promote Duolingo, and depreciation of certain property and equipment. Advertising costs were approximately $48,111, $42,964 and $27,352 for the years ended December 31, 2022, 2021 and 2020, respectively.

General and Administrative—General and administrative expense primarily consists of employee related compensation (including stock-based compensation) for management and administrative functions, including our finance and accounting, legal, and people teams. General and administrative expense also includes certain professional services fees, general corporate and director and officer insurance, facilities costs, and other general overhead costs that support our operations, and depreciation of certain property and equipment.

Contributors—On March 10, 2021, the Company announced that it was ending its non-employee volunteer program, which began in 2013 to build and improve language courses. As part of this change, those contributors who participated in the program became eligible to receive a one-time award, up to an aggregate amount of approximately $4,220, including fees paid to process payments of approximately $526. The Company accounted for this under Financial Accounting Standards Board (“FASB”) Accounting Standards Codifications (“ASC”) 958-720, Not-For-Profit Entities - Other Expenses and ASC 720-25, Contributions Made, based on the nature of this contribution, which is an unconditional promise. This amount is included within Sales and marketing in the Consolidated Statements of Operations and Comprehensive Loss.

Concentration of Credit Risk—The Company’s concentration of credit risk relates to financial institutions holding the Company’s cash and cash equivalents and platforms with significant accounts receivable balances and revenue transactions.

The Company maintains cash deposits with financial institutions that may exceed federally insured limits at times. Management believes that the financial institutions that hold the Company’s deposits are financially credit worthy and, accordingly, minimal credit risk exists with respect to those balances.

The majority of our revenue comes through our subscriptions and advertising streams and payments are made to Duolingo through service providers. The top two, Apple and Google, accounted for 56.2% and 27.5% of total Accounts receivable as of December 31, 2022, respectively. The top three service providers, Apple, Google and Stripe, accounted for 51.1%, 27.9% and 10.1% of total Accounts receivable as of December 31, 2021, respectively.

Two service providers, Apple and Google, processed 54.2% and 28.1% of total Revenues for the year ended December 31, 2022, respectively. Three services providers, Apple, Google, and Stripe, processed 50.5%, 29.0% and 10.1% of total Revenues for the year ended December 31, 2021, respectively. Two service providers, Apple and Google, processed 51.3% and 26.9% of total Revenues for the year ended December 31, 2020, respectively.

Stock-Based Compensation—The Company accounts for equity-based compensation using the fair value method as set forth in the ASC 718, Compensation—Stock Compensation, which requires the measurement and recognition of compensation expense for all stock-based payment awards based on estimated fair values. This method requires companies to estimate the fair value of stock-based compensation on the date of grant using an option pricing model. The Company estimates the fair value of each equity-based payment award on the date of grant using the Black-Scholes pricing model.

The Black-Scholes model determines the fair value of equity-based payment awards based on the fair value of the underlying common stock on the date of grant and requires the use of estimates and assumptions, including the fair value of the Company’s common stock, exercise price of the stock option, expected volatility, expected life, risk-free interest rate and dividend rate. The Company estimates the expected volatility of its stock options by taking the average historical volatility of a group of comparable publicly traded companies over a period equal to the expected life of the options; it is not practical for the Company to estimate its own volatility due to the lack of historical prices. The expected term of the options is determined in accordance with existing equity agreements as the underlying options are assumed to be exercised upon the passage of time. The risk-free interest rate is the estimated average interest rate based on US Treasury zero-coupon notes with terms consistent with the expected life of the awards. The expected dividend yield is zero as the Company does not anticipate paying any recurring cash dividends in the foreseeable future. The Company accounts for forfeitures as they occur.

Restricted Stock Units (RSUs)

The Company began to grant RSUs in November 2020. The fair value of RSUs is estimated based on the fair value of the Company’s common stock on the date of grant. Each RSU award granted prior to the IPO vests based upon the satisfaction, during the term of the RSUs, of two requirements: length of service and a liquidity event defined as a change in control or a qualified IPO. The service-based vesting condition for the majority of these awards is satisfied over four years. The liquidity-based vesting condition is satisfied upon the occurrence of a qualifying liquidity event. The Company measures and recognizes compensation expense for all stock-based awards based on the estimated fair value of the award. Prior to July 30, 2021, no stock-based compensation expense had been recognized for RSUs because the liquidity-based vesting condition had not been probable of being satisfied. Upon the IPO, the liquidity-based vesting condition was satisfied and $2,035 of stock-based compensation expense was recognized related to these awards during the year ended December 31, 2021. Of that amount, $1,332, $210 and $493 was included within Research and development, Sales and marketing and General and administrative, respectively, in the Consolidated Statement of Operations and Comprehensive Loss.

Performance-based RSUs

In June 2021, the Company granted 1,800 (one million eight-hundred thousand) performance-based RSUs to the Company’s founders (“Founder Awards”). The Founder Awards are divided into ten equal tranches with each tranche becoming eligible to vest upon achievement of the specified stock-price hurdles. The Founder Awards vest upon the satisfaction of both a service-based condition and a performance-based condition and generally are settled one year after vesting. The service-based condition is satisfied as to 25% of the Founder Awards on each anniversary of the completion of the IPO, subject to the continuous service of the founders through the applicable date. The fair value of the Founder Awards is determined using a Monte Carlo simulation model. The associated stock-based compensation is recorded over the derived service period, using the accelerated attribution method. If the stock-price hurdles are met sooner than the requisite service period, the stock-based compensation expense will be adjusted to prospectively recognize the remaining expense over the remaining derived service period. Provided that the founders continue to provide services to us, stock-based compensation expense is recognized over the derived service period, regardless of whether the stock-price hurdles are achieved. The first and second tranches were met during the year ended December 31, 2021. The Company recognized $30,997 of stock-based compensation expense related to these awards, which is included within General and administrative in the Consolidated Statements of Operations and Comprehensive Loss.

Contingencies—The Company records accruals for contingencies and legal proceedings expected to be incurred in connection with a loss contingency when it is probable that a liability has been incurred and the amount can be reasonably estimated.

If a loss contingency is not probable, but is reasonably possible, or is probable but cannot be estimated, the nature of the contingent liability, together with an estimate of the range of possible loss, would be disclosed.

Segment—The Company operates as a single operating segment. The chief operating decision maker of the Company is its Chief Executive Officer, who makes resource allocation decisions and assesses performance based on financial information presented on a consolidated basis, accompanied by disaggregated information of our revenue. Accordingly, the Company has determined that it has a single reportable segment and operating segment structure, and operates as one reporting unit.

sheet with a right-of-use (“ROU”) asset and corresponding lease liability. ROU assets are periodically reviewed for impairment whenever events or changes in circumstances arise. During the years ended December 31, 2022, 2021 and 2020, the Company incurred no impairment charges on ROU assets.

On the lease commencement date, each lease is classified as either finance or operating, depending on certain criteria. The Company determined that it only has operating leases as none of the criteria for finance lease classification were met. Operating lease expense is recognized on a straight-line basis on the Consolidated Statements of Operations and Comprehensive Loss in General and administrative expenses. On the Consolidated Statements of Changes in Cash Flows, payments for operating leases, are included in operating activities. As an accounting policy election, the Company has elected to not separate lease and non-lease components for all asset classes and made an accounting policy election for short-term leases which does not require the capitalization of leases with terms of 12 months or less at lease commencement. The discount rate utilized in calculating the lease liability is the rate implicit in the lease, if known; otherwise, the incremental borrowing rate (“IBR”) for the expected lease term is used. The Company’s IBR approximates the rate the Company would have to pay, on a collateralized basis, to borrow an amount equal to the lease payments under similar terms.

Impairment of long-lived assets— The Company reviews its long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. If the sum of the estimated undiscounted future cash flows expected to result from the use and eventual disposition of an asset is less than the carrying amount of the asset, an impairment loss is recognized. Measurement of an impairment loss is based on the fair value of the asset. No assets were impaired during the years ended December 31, 2022, 2021 and 2020.

Recently Issued Pronouncements Not Yet Adopted

There are no recently issued accounting pronouncements that the Company has not yet adopted that they believe are applicable or would have a material impact on the financial statements of the Company.

Recently Adopted Accounting Pronouncements

There are no recently adopted accounting pronouncements.

ACQUISITION	12 Months Ended
ACQUISITION	Dec. 31, 2022
Business Combination and Asset Acquisition [Abstract]
ACQUISITION	ACQUISITION On October 3, 2022, the Company completed the acquisition of the assets of Gunner Made LLC (“Gunner”), a wholly owned entity of PNG Holdings LLC, a design and animation studio based in Detroit, Michigan. The acquisition of Gunner added fifteen new designers, illustrators, and animators to Duolingo’s existing design teams. The total consideration was $4.5 million, of which $4 million was purchase price paid in cash upon closing and was allocated to Goodwill within the Consolidated Financial Statements as it was determined that no other separately identifiable assets were acquired. The remaining $450 will be paid after one year of continued service of certain Gunner employees, and will be expensed over the period within General and administrative in the Consolidated Statements of Operations and Comprehensive Loss. The Company incurred $50 of acquisition costs related to due diligence and valuation, and they are included in General and administrative expense within the Consolidated Statements of Operations and Comprehensive Loss. The Company assumed a new lease for office space as part of the Gunner acquisition. The term of the newly acquired lease is 68 months beginning on October 3, 2022 and expiring on May 31, 2028. The Company has the option to extend the lease for one additional term of five years and one additional term of four years which the Company has not included in the lease term. The remaining payments related to this lease agreement as of December 31, 2022 are approximately $750. The Company reviewed the lease, and determined that the current terms were relative to current market conditions, and as such, no intangible asset was created. The Company also signed an agreement to sublease a portion of the acquired lease. The term of the sublease is 68 months beginning on October 3, 2022 and expiring on May 31, 2028. The remaining receivable related to this sublease agreement as of December 31, 2022 is approximately $358.

REVENUE

12 Months Ended

Dec. 31, 2022

Revenue from Contract with Customer [Abstract]

REVENUE

The Company has three predominant sources of revenues; time-based subscriptions, in-app advertising placement by third parties, and the Duolingo English Test. Revenue is recognized upon transfer of control of promised products or services to users in an amount that reflects the consideration the Company expects to receive in exchange for those services. The Company does not enter into contracts with a customer that contain multiple promises that result in multiple performance obligations. Revenue is recorded net of taxes assessed by a government authority that are both imposed on and concurrent with specific revenue transactions between us and our users.

Revenue from time-based subscriptions includes a stand-ready obligation to provide hosting services that are consumed by the customer over the subscription period. Users can purchase Duolingo monthly or they can purchase a six-month or year-long subscription and pay for the subscription at the time of purchase. Under the year-long subscription, users can also purchase a single plan or a family plan. The family plan includes up to six users on one subscription. Such payments are initially recorded to deferred revenue. The user has the ability to download limited content offline. However, as there is a significant level of integration and interdependency with the online functionality, the Company considers the service to be a single performance obligation for the online and offline content.

The Company enters into arrangements with advertising networks to monetize the in-app advertising inventory. Revenue from in-app advertising placement is recognized at a point in time when the advertisement is placed and is based upon the amount received.

Duolingo English Test revenue is generally recognized once the tests have gone through the proctoring process and a certification decision has been made. This process usually takes less than 48 hours after the test has been completed and uploaded. Customers have 21 days from the date of purchase to take the exam or their purchase will expire and revenue will be recognized. Virtually all customers complete their exams prior to expiration. Sometimes organizations may purchase tests in bulk via coupons with a one year expiration date. The Company will defer revenue from all tests that have neither been proctored nor expired.

The Company’s users have the option to purchase consumable in-app virtual goods. The Company recognizes revenue over the period in which the user consumes the virtual good, which is generally within a month.

The Company also recognizes revenue from Duo’s Taquería, a restaurant that opened during 2022, in the space adjacent to our headquarters in Pittsburgh. Revenue from Duo’s Taquería is recognized at a point in time when the sales are made.

Principal Agent Considerations—The Company makes its application available to be downloaded through third-party digital distribution service providers. Users who purchase subscriptions also pay through the respective app stores. The Company evaluates the purchases via third-party payment processors to determine whether its revenues should be reported gross or net of fees retained by the payment processor. The Company is the principal in the transaction with the end user as a result of controlling, hosting, and integrating the delivery of the virtual items to the end user. The Company records

revenue gross as a principal and records fees paid to third-party payment processors as Cost of revenues.

Contract Balances—Deferred revenue mostly consists of payments we receive in advance of revenue recognition, and is mostly related to time-based subscriptions, which will be recognized into revenue over the course of the upcoming year (recognized over 12 months or less). Additionally, the Duolingo English Test has deferred revenue related to tests that have been purchased, but will not be recognized until the tests have been proctored.

Disaggregation of Revenue

In accordance with ASC 606, Revenue from Contracts with Customers, the Company disaggregates revenue from contracts with customers into revenue stream, which most closely depicts how the nature, amount, timing and uncertainty of revenue and cash flows are affected by economic factors.


	Year Ended December 31,
		2022		2021		2020
Revenues:
Subscription		$	273,507	$	180,698	$	117,501
Advertising		44,731		38,501		27,043
Duolingo English Test		32,718		24,658		15,155
Other (1)		18,539		6,915		1,997
Total revenues		$	369,495	$	250,772	$	161,696

________________

(1) Other revenue is mainly comprised of in-app purchases of virtual goods.

Information regarding geography of revenues is based upon the location where the users are located or, in the case of the Duolingo English Test, where the tests are taken:


	Year Ended December 31,
	2022		2021		2020
United States	$	168,320	$	109,163	$	70,978
United Kingdom	31,539		25,163		15,245
Rest of World	169,636		116,446		75,473
Total	$	369,495	$	250,772	$	161,696

Customers located in the United States accounted for 46% of total revenues for the year ended December 31, 2022, and 44% of total revenues for both of the years ended December 31, 2021 and 2020, and customers located in the United Kingdom accounted for 9%, 10% and 9% for the years ended December 31, 2022, 2021 and 2020, respectively. No other country accounted for more than 10% of revenue in the periods presented.

Changes in deferred revenues were as follows:


	Year Ended December 31,
	2022		2021
Beginning balance—January 1	$	98,267	$	54,792
Amount from beginning balance recognized into revenue	(98,267)		(54,792)
Recognition of deferred revenue	(199,130)		(139,371)
Deferral of revenue	356,680		237,638
Ending balance—December 31	$	157,550	$	98,267

- Definition

The entire disclosure of revenue from contract with customer to transfer good or service and to transfer nonfinancial asset. Includes, but is not limited to, disaggregation of revenue, credit loss recognized from contract with customer, judgment and change in judgment related to contract with customer, and asset recognized from cost incurred to obtain or fulfill contract with customer. Excludes insurance and lease contracts.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-URI https://asc.fasb.org/topic&trid=49130388

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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-URI https://asc.fasb.org/extlink&oid=126920106&loc=SL49130554-203045

+ Details

PROPERTY and EQUIPMENT, net

12 Months Ended

Dec. 31, 2022

Property, Plant and Equipment [Abstract]

PROPERTY and EQUIPMENT, net

Property and equipment consists of the following as of December 31, 2022 and December 31, 2021:



	2022		2021
Leasehold improvements	$	15,983	$	10,258
Furniture, fixtures and equipment	5,204		3,053
Total property and equipment	21,187		13,311
Less: accumulated depreciation	(8,218)		(5,100)
Total property and equipment, net	$	12,969	$	8,211

Depreciation expense of $3,118, $2,033 and $1,624 for the years ended December 31, 2022, 2021, and 2020 respectively, is recorded in the Company’s Consolidated Statements of Operations and Comprehensive Loss. Depreciation expense is included within the following financial statement line items within the Company’s Consolidated Financial Statements.


	Year Ended December 31,
(In thousands)		2022		2021		2020

Research and development		$	1,500	$	260	$	—
Sales and marketing		190		32		—
General and administrative		1,428		1,741		1,624
Total		$	3,118	$	2,033	$	1,624

INTANGIBLE ASSETS AND GOODWILL

12 Months Ended

Dec. 31, 2022

Goodwill and Intangible Assets Disclosure [Abstract]

INTANGIBLE ASSETS AND GOODWILL

Intangible assets consist mostly of capitalized software, with $18 and $0 of other intangible assets as of December 31, 2022 and December 31, 2021, respectively.


	2022		2021
Intangible assets	$	16,827	$	11,144
Less: accumulated amortization	(8,330)		(6,578)
Intangible assets, net	$	8,497	$	4,566

The Company capitalized $5,665 and $2,963 of software development costs during the years ended December 31, 2022 and 2021, respectively. Amortization expense of $1,752, $693 and $632 for the years ended December 31, 2022, 2021 and 2020 respectively, is recorded in the Company’s Consolidated Statements of Operations and Comprehensive Loss. Amortization expense is included within the following financial statement line items within the Company’s Consolidated Financial Statements.


	Year Ended December 31,
(In thousands)		2022		2021		2020
Cost of revenues		$	870	$	—	$	86
Sales and marketing		882		693		546
Total		$	1,752	$	693	$	632

Changes in the carrying amount of goodwill are as follows:


(in thousands)	Amount
Balance as of December 31, 2021	$	—
Acquisition	4,050
Balance as of December 31, 2022	$	4,050

As of December 31, 2022, $3,983 of goodwill is deductible for tax purposes.

LEASES

12 Months Ended

Dec. 31, 2022

Leases [Abstract]

LEASES

The Company has entered into various operating leases for its office space expiring between fiscal 2023 and 2035. Certain lease agreements contain an option for the Company to renew a lease for a term of up to five years. The Company considers these options, which may be elected at the Company’s sole discretion, in determining the lease term on a lease-by-lease basis.

The following represents the components of lease cost for the years ended December 31, 2022, 2021 and 2020 along with supplemental disclosures of cash flow information, lease term and discount rate:


	Year Ended December 31,
	2022			2021			2020
Operating lease cost	$	7,076		$	1,919		$	1,721
Short term lease cost	125			1,266			317
Variable lease cost	63			28			—
Total lease cost	$	7,264		$	3,213		$	2,038

Cash paid for amounts included in the measurement of lease liabilities	$	5,168		$	1,819		$	—
Right-of-use assets obtained in exchange for new operating lease liabilities	$	909		$	22,274		$	—
Right of use assets disposed or adjusted, modifying operating leases liabilities	$	(1,586)		$	(235)		$	—
Gain from termination of leases	$	—		$	31		$	—
Weighted-average remaining lease term	9 years			9 years			8 years, 11 months
Weighted-average discount rate	6.92		%	5.77		%	6.70		%

The following table reconciles future minimum undiscounted rental commitments for operating leases to operating lease liabilities recorded on the Consolidated Balance Sheet as of December 31, 2022:


Fiscal year
2023	$	6,719
2024	4,702
2025	3,239
2026	3,310
2027	3,371
Thereafter	18,834
Total undiscounted lease payments	$	40,175
Present value adjustment	(11,769)
Operating lease liabilities	$	28,406

Current lease liabilities of $4,903 and $3,336 are presented within Accrued expenses and other liabilities while non-current lease liabilities of $23,503 and $29,124 are presented within Long-term obligation under operating leases on the Consolidated Balance Sheets for the years ended December 31, 2022 and 2021 respectively.

INCOME TAXES

12 Months Ended

Dec. 31, 2022

Income Tax Disclosure [Abstract]

INCOME TAXES

For the years ended December 31, 2022, 2021 and 2020 the Company recognized the following provision for income taxes:


	Year Ended December 31,
	2022		2021		2020
Current:
Federal	$	302	$	—	$	—
State	327		80		42
Foreign	524		97		26
Total	$	1,153	$	177	$	68

Deferred:
Federal	$	—	$	—	$	—
State	—		—		—
Foreign	(215)		—		—
Total	$	(215)	$	—	$	—

Total provision for income taxes	$	938	$	177	$	68

The provision for income taxes differs from the amounts computed by applying the federal statutory rate as follows for the years ended December 31, 2022, 2021 and 2020:


	2022		2021		2020
Federal statutory rate	21.0	%	21.0	%	21.0	%
State taxes	6.7		6.5		1.8
Section 162(m) limitation	(15.2)		(13.5)		—
Equity compensation	28.4		53.8		(18.4)
Other permanent adjustments	(0.9)		(0.5)		(1.8)
Research and development credit	11.7		15.9		10.2
Valuation allowance	(53.3)		(83.5)		(13.2)
Effective income tax rate	(1.6)	%	(0.3)	%	(0.4)	%

The 2022, 2021 and 2020 effective tax rate is less than the statutory rate primarily as a result of the valuation allowance for net deferred tax assets.

The Company has the following deferred tax assets (liabilities) as of December 31, 2022 and 2021:


	2022		2021
Net operating loss carryforwards	$	42,861	$	61,605
Equity compensation	3,605		1,881
Research and development credits	22,386		14,480
Lease liability	6,487		7,335
Section 174 research and development capitalization	42,429		—
Marketing and advertising	633		—
Sales tax / Value added tax ("VAT") reserve	210		277
Other deferred tax assets	140		56
Valuation allowance	(108,504)		(76,293)
Total deferred tax assets	10,247		9,341

ROU asset	(5,122)		(6,389)
Property and equipment	(2,569)		(1,894)
Capitalized software	(1,913)		(1,057)
Other deferred tax liabilities	(10)		(1)
Total deferred tax liabilities	(9,614)		(9,341)

Net deferred taxes	$	633	$	—

The Company has provided a full valuation allowance for its US federal and state net deferred tax asset as it is not more likely than not that the asset will be realized. The movement in valuation allowance of $32,211 is primarily related to the capitalization, for U.S. income tax purposes, of research and development expenditures. During 2022, the Company established a deferred tax asset with respect to its China subsidiary.

The following table represents the activity in our valuation allowance for the years ended December 31, 2022 and 2021:


	Year Ended December 31,
	2022		2021
Beginning balance—January 1	$	(76,293)	$	(26,236)
Valuation allowances established	(32,211)		(50,057)
Release of valuation allowances	—		—
Ending balance—December 31	$	(108,504)	$	(76,293)

The Company has approximately $172,046 in federal net operating loss carryforwards and approximately $86,164 in state net operating loss carryforwards. Certain of these loss carryforwards have an indefinite life and other amounts are available to offset future taxable income through 2041. The Company has approximately $22,387 in federal and state general business credits that are available to offset future taxable income through 2041. The Company has analyzed the impact of Internal Revenue Code (“IRC”) Sections 382 and 383 on these tax attributes and has determined that no prior ownership changes have occurred which would limit the Company’s ability to utilize the NOLs and research and development tax credits.

The Company’s tax years through the 2022 tax year remain subject to examination by federal and state tax authorities.

The Company utilizes a more-likely-than-not standard in recognizing a tax benefit in its financial statements. No uncertain tax benefits have been recorded in 2022, 2021, and 2020, respectively.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 21
-URI https://asc.fasb.org/extlink&oid=121826272&loc=d3e32857-109319

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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

CONVERTIBLE PREFERRED STOCK

12 Months Ended

Dec. 31, 2022

Temporary Equity Disclosure [Abstract]

CONVERTIBLE PREFERRED STOCK

Immediately prior to the completion of the IPO on July 30, 2021, all convertible preferred stock outstanding, totaling approximately 19,074 shares, was automatically converted into an equivalent number of shares of Class B common stock on a one-to-one basis and their carrying value of $182,609 was reclassified to additional paid-in capital within stockholders’ equity (deficit).

The following table summarizes the convertible preferred stock outstanding immediately prior to the conversion into common stock and as of December 31, 2020:


	Shares
Series	Authorized	Outstanding	Per share price at issuance		Aggregate liquidation preference		Funds received		Fees incurred		Carrying value of convertible preferred stock
A	3,865	3,865	$	0.85	$	3,300	$	3,300	$	52	$	3,248
B	6,298	6,298	2.38		$	15,000	$	15,000	$	60	$	14,940
C	2,948	2,948	6.78		$	20,000	$	20,000	$	112	$	19,888
D	3,154	3,154	14.27		$	45,000	$	45,000	$	146	$	44,853
E	1,224	1,224	20.43		$	25,000	$	25,000	$	92	$	24,909
F	758	758	39.57		$	30,000	$	30,000	$	153	$	29,848
G	241	241	41.38		$	10,000	$	10,000	$	24	$	9,976
H	586	586	59.77		$	35,000	$	35,000	$	52	$	34,947
Total	19,074	19,074			$	183,300	$	183,300	$	691	$	182,609

STOCK-BASED COMPENSATION

12 Months Ended

Dec. 31, 2022

Equity [Abstract]

STOCK-BASED COMPENSATION

Prior to the IPO, the Company granted options to purchase shares of the Company’s common stock and restricted stock units (“RSU”) in respect of shares of the Company’s common stock to employees, directors and consultants under the Company’s 2011 Equity Incentive Plan. In July 2021, Duolingo adopted the 2021 Incentive Award Plan (“2021 Plan”) and the 2021 Employee Stock Purchase Plan (“ESPP”), each of which became effective on July 26, 2021 in connection with the IPO. An aggregate of 7,946 shares and 1,119 shares of Class A common stock were made available for future issuance under the 2021 Plan and ESPP, respectively. On each January 1, the number of shares of the Company’s Class A common stock available for issuance under the 2021 Plan have been, and through January 1, 2031, will be, increased by the lesser of (i) 5% of the shares outstanding on the preceding December 31 (calculated on an as-converted basis) and (B) such smaller number of shares of common stock as determined by the Board or the Committee (as defined in the 2021 Plan). On January 1, 2022, the 2021 Plan and ESPP were increased by 1,913 shares and 166 shares, respectively. On January 1, 2023, the 2021 Plan and ESPP were increased by 2,018 shares and 319 shares, respectively.

The Company’s stock options vest based on terms in the stock option agreements, which generally provide for vesting over four years based on continued service to the Company and its subsidiaries. Each option has a term of ten years. Stock options granted under the 2021 Plan must generally have an exercise price of not less than the estimated fair market value of the underlying Class A common stock at the date of the grant. No options have been granted under the 2021 Plan.

A summary of stock option activity under the Plans was as follows:


	Number of options	Weighted- average exercise price		Weighted- average remaining contractual life (years)	Aggregate intrinsic value





Options outstanding at January 1, 2022	6,255	$	12.53	6.92	$	585,339
Granted (1)	—
Exercised	(1,739)	8.47
Repurchased	—
Forfeited and expired	(106)	16.47
Options outstanding at December 31, 2022	4,410	$	14.04	6.25	$	251,832
Options exercisable at December 31, 2022	3,689	$	13.08	6.03	$	214,131

________________

(1) There were no stock options granted during the year ended December 31, 2022

The total intrinsic value of options exercised was approximately $140,884, $194,513, and $6,058 for the periods ended December 31, 2022, 2021 and 2020, respectively.

The fair value of each option grant is estimated on the date of grant using the Black-Scholes option pricing model with the following assumptions:

2022

2021

2020

Risk-free interest rate

n/a

1.04 – 1.14%

0.32 – 0.68%

Expected life

n/a

5.90 years

6.01 years

Expected volatility

n/a

48.90 – 49.12%

45.50 – 49.38%

Dividend yield

n/a

—%

Fair value of common stock

n/a

$38.08 – $52.80

$14.42 – $38.08

The risk-free interest rate is based on the US treasury yield curve in effect as of the grant date. When establishing the expected life assumptions, the Company annually reviews historical employee exercise behavior of option grants and other economic data impacting the period the stock options are expected to remain outstanding. Expected volatility is determined using a benchmark index of similar public companies. The Company based the assumed dividend yield on its expectation of not paying dividends in the foreseeable future. Because the Company’s common stock was not yet publicly traded at the time the options were granted, the Company estimated the fair value of common stock. The Board estimated the fair value of the common stock at the time awards were granted based on factors such as valuations of comparable companies, the status of the Company’s development and sales efforts, revenue growth, and additional objective and subjective factors relating to the Company’s business.

A summary of RSU activity under the Plans was as follows:


	Restricted stock units	Weighted- average grant date fair value per share




Outstanding at January 1, 2022	730	$	77.09
Granted	1,755	88.56
Released	(350)	82.26
Forfeited	(99)	84.30
Outstanding at December 31, 2022	2,036	$	85.74

Prior to July 30, 2021, no stock-based compensation expense had been recognized for RSUs because the liquidity-based vesting condition had not been probable of being satisfied. Upon the IPO, the liquidity-based vesting condition was met and $2,035 of stock-based compensation expense was recognized related to these awards.

As of December 31, 2022, there was approximately $5,663 of unrecognized compensation cost related to stock options granted under the plans with a weighted-average period of approximately one year. The amount of unrecognized compensation expense for RSUs as of December 31, 2022 was $163,724 with a weighted-average period of approximately three years, for a total unrecognized compensation expense of $169,387.

There were 8,117 shares available for grant at December 31, 2022.

Performance-based RSUs

In June 2021, the Company granted an aggregate of 1,800 performance-based RSUs (the “Founder Awards”) to the Company’s founders. The Founder Awards vest upon the satisfaction of both a service-based condition and a performance-based condition and generally are settled one year after vesting. The service-based condition is satisfied as to 25% of the Founder Awards on each anniversary of the

completion of the IPO, subject to the continuous service of the founders through the applicable date. The performance-based condition will be satisfied with respect to each of 10 equal tranches only if the trailing 60-calendar day volume-weighted-average closing trading price of the Company’s Class A common stock reaches certain stock-price hurdles for each such tranche, as set forth below, over a period of 10 years from the date of grant.

Any RSUs associated with stock-prices hurdle not achieved by the tenth anniversary of the date of grant will terminate and be canceled for no additional consideration to the founders. The stock-price hurdles and number of RSUs eligible to vest will be adjusted to reflect any stock splits, stock dividends, combinations, reorganizations, reclassifications, or similar events under the 2021 Plan. The Founder Awards will be settled in shares of the Company’s Class B common stock.


Tranche	Company Stock Price Hurdle		Number of RSUs Eligible to Vest
1	$	127.50	90
2	$	153.00	90
3	$	178.50	90
4	$	204.00	180
5	$	255.00	180
6	$	306.00	180
7	$	357.00	180
8	$	408.00	180
9	$	612.00	270
10	$	816.00	360

The Company estimated the grant date fair value of the Founder Awards using a model based on multiple stock-price paths developed through the use of a Monte Carlo simulation that incorporates into the valuation the possibility that the stock-price hurdles may not be satisfied. The weighted-average grant date fair value of the Founder Awards was estimated to be $61.56 per share using the below inputs.


Input			Assumption
Valuation Date			June 28, 2021
Risk-free interest rate			1.48%
Expected life			9.98
Expected volatility			51.67%
Dividend yield			0.00%
Fair value of common stock			$95.00

The Company estimates that it will recognize total stock-based compensation expense of approximately $110,817 over the derived service period of each of the ten separate tranches which is between 3.58 – 5.92 years. If the stock-price hurdles are met sooner than the requisite service period, the stock-based compensation expense will be adjusted to prospectively recognize the remaining expense over the remaining derived service period. Provided that the founders continue to provide services to the Company, stock-based compensation expense is recognized over the derived service period, regardless of whether the stock-price hurdles are achieved. The stock-price hurdles for the first two tranches were met during 2021. No additional stock-price hurdles were met during the year ended December 31, 2022. The Company recognized $30,997 and $16,463 of stock-based compensation expense related to these awards for the years ended December 31, 2022 and 2021, respectively, which is included within General

and administrative in the Consolidated Statements of Operations and Comprehensive Loss. As of December 31, 2022, there is $63,357 of unrecognized compensation expense related to these awards.

In February 2021, the Company initiated a tender offer which allowed employees to sell up to 10% of their vested options or shares back to the Company at selling price of $59.77, which was above fair market value of $38.08. The Company paid $13,479 and incurred $5,275 of additional compensation expense related to this tender representing the difference between the aggregate selling price and fair market value of the options and shares sold, and a $7,335 decrease to Additional paid-in capital. As a result of this tender, 220 options were put back into the option pool and 23 shares were retired with an $868 decrease to Additional paid-in capital.

Upon the IPO, vesting of stock option grants to certain executive officers were accelerated, which resulted in an additional $5,574 of compensation expense during the year ended December 31, 2021. This is included within General and administrative in the Consolidated Statements of Operations and Comprehensive Loss.

Total stock-based compensation expense was $73,820, $40,804 and $17,031 for the year ended December 31, 2022, 2021 and 2020, respectively.

Stock based compensation expense is included in the Consolidated Statements of Operations and Comprehensive Loss as shown in the following table:


	Year Ended December 31,
		2022		2021		2020
Cost of revenues		$	38	$	8	$	6
Research and development		26,373		9,298		2,773
Sales and marketing		2,540		881		348
General and administrative		44,869		30,617		13,904
Total		$	73,820	$	40,804	$	17,031

Nominal amounts of stock based compensation expense is capitalized into intangible assets for the years ended December 31, 2022, 2021 and 2020.

COMMITMENTS AND CONTINGENCIES	12 Months Ended
COMMITMENTS AND CONTINGENCIES	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Legal Proceedings— From time to time, the Company may become involved in various legal proceedings in the ordinary course of its business and may be subject to third-party infringement claims. The outcome of any such claims or proceedings, regardless of the merits, is inherently uncertain. The Company is not currently party to any material legal proceedings. Related Parties— The Company has determined that there were no transactions with related parties as of or during the years ended December 31, 2022, 2021, and 2020.

ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES

12 Months Ended

Dec. 31, 2022

Other Liabilities Disclosure [Abstract]

ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES

ACCRUED EXPENSES AND OTHER CURRENT LIABILITIESAccrued expenses and other current liabilities consisted of the following:


	December 31, 2022		December 31, 2021
Obligations under current leases	$	4,903	$	3,336
Employee-related costs	4,233		2,075
Marketing related accruals	3,464		1,078
Sales and VAT tax accrual	2,396		2,319
Other	6,974		4,125
Total	$	21,970	$	12,933

EMPLOYEE BENEFIT PLAN	12 Months Ended
EMPLOYEE BENEFIT PLAN	Dec. 31, 2022
Postemployment Benefits [Abstract]
EMPLOYEE BENEFIT PLAN	EMPLOYEE BENEFIT PLANThe Company sponsors a profit sharing plan with a 401(k) feature, the Duolingo Retirement Plan, (the “Plan”) for eligible employees. The current Plan, effective January 1, 2021, provides for Company safe harbor matching contributions of 100% of the first 4% of the employees’ elective deferrals and 50% of the next 2%, with vesting starting upon the first day of employment. The prior Plan provided for Company safe harbor matching contributions of 100% of the first 3% of the employees’ elective deferrals and 50% of the next 2%, with vesting starting upon the first day of employment. The Company also has the option to make discretionary matching or profit sharing contributions. The Company made safe harbor matching contributions of approximately $4,624, $3,438 and $1,796 for the years ended December 31, 2022, 2021 and 2020, respectively. The Company did not make any discretionary matching or profit sharing contributions during the years ended December 31, 2022, 2021, or 2020.

LOSS PER SHARE

12 Months Ended

Dec. 31, 2022

Earnings Per Share [Abstract]

LOSS PER SHARE

Basic and diluted net loss per share attributable to common stockholders is presented in conformity with the two-class method required for participating securities. Prior to the automatic conversion of all of its convertible preferred stock outstanding into Class B common stock upon the IPO, the Company considered all series of its convertible preferred stock to be participating securities.

Under the two-class method, the net loss attributable to common stockholders is not allocated to the convertible preferred stock as the holders of the convertible preferred stock do not have a contractual obligation to share in the Company’s losses. Basic net loss per share attributable to common stockholders is calculated by dividing the net loss by the weighted-average number of shares of common stock outstanding during the period, less shares subject to repurchase. The diluted net loss per share attributable to common stockholders is calculated by giving effect to all potential dilutive common stock equivalents outstanding for the period.


	Year Ended December 31,
(In thousands, except per share data)		2022		2021		2020
Numerator:
Net loss attributable to Class A and Class B common stockholders		$	(59,574)	$	(60,135)	(15,776)


Denominator:
Weighted-average shares in computing net loss per share attributable to Class A and Class B common stockholders, basic and diluted		39,470		23,433		12,735




Basic loss per common share		$	(1.51)	$	(2.57)	$	(1.24)
Diluted loss per common share		$	(1.51)	$	(2.57)	$	(1.24)

The rights, including the liquidation and dividend rights, of the holders of Class A and Class B common stock are identical, except with respect to voting and conversion. Each share of Class A common stock is

entitled to one vote per share and each share of Class B common stock is entitled to 20 votes per share. Each share of Class B common stock is convertible into a share of Class A common stock voluntarily at any time by the holder, and automatically upon certain events. The Class A common stock has no conversion rights. As the liquidation and dividend rights are identical for Class A and Class B common stock, the undistributed earnings are allocated on a proportional basis and the resulting net loss per share attributable to common stockholders will, therefore, be the same for both Class A and Class B common stock on an individual or combined basis.

Since the Company was in a net loss position for the years ended December 31, 2022, 2021, and 2020 there is no difference between the number of shares used to calculate basic and diluted loss per share. The potential shares of common stock that were excluded from the computation of diluted net loss per share attributable to common stockholders for the period presented because including them would have been antidilutive are as follows:


	Year Ended December 31,
(in thousands)	2022	2021	2020
Convertible preferred stock	—	—	19,074
Founder awards where performance has been met	180	180	—
Stock options outstanding (1)	4,410	6,255	8,365
RSUs outstanding (1)	2,036	730	34
Total	6,626	7,165	27,473

________________

(1) Prior year amounts were adjusted in the current year table to include unvested options and RSUs

Founder awards of 1,620, where the performance criteria has not been satisfied, are excluded from the above table because the stock-price hurdles for those awards had not been met as of December 31, 2022 and 2021.

SUBSEQUENT EVENTS	12 Months Ended
SUBSEQUENT EVENTS	Dec. 31, 2022
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	SUBSEQUENT EVENTSNone

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)

12 Months Ended

Dec. 31, 2022

Accounting Policies [Abstract]

Principles of Consolidation

Principles of Consolidation—The Consolidated Financial Statements include the accounts of the Company and subsidiaries over which the Company has control. All intercompany transactions and balances have been eliminated.

Basis of Presentation and Accounting Principles

Basis of Presentation—The accompanying Consolidated Financial Statements have been prepared in accordance with generally accepted accounting principles in the United States (“GAAP”) from the Company’s accounting records and reflect the consolidated financial position and results of operations for the years ended December 31, 2022, 2021 and 2020. Unless otherwise specified, all dollar amounts are referred to in thousands.Accounting Principles—The Consolidated Financial Statements and accompanying notes are prepared in accordance with GAAP.

Use of Estimates

Use of Estimates—The preparation of Consolidated Financial Statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the Consolidated Financial Statements and accompanying notes. Significant estimates and assumptions reflected in the Consolidated Financial Statements include, but are not limited to, useful lives of property and equipment, valuation of deferred tax assets and liabilities, stock-based compensation, common stock valuation, operating lease right-of-use assets and liabilities, capitalization of internally developed software and associated useful lives and contingent liabilities. Actual results may differ materially from such estimates. Management believes that the estimates, and judgments upon which they rely, are reasonable based upon information available to them at the time that these estimates and judgments are made. To the extent that there are material differences between these estimates and actual results, the Company’s Consolidated Financial Statements will be affected.

Revenue Recognition

REVENUE

revenue gross as a principal and records fees paid to third-party payment processors as Cost of revenues.

Disaggregation of Revenue

Cash and Cash Equivalents

Cash and Cash Equivalents—Cash consists primarily of cash on hand and bank deposits. Cash equivalents consist primarily of money market accounts with maturities of three months or less at the date of acquisition and are stated at cost, which approximates fair value. The Company maintains cash deposits with financial institutions that may exceed federally insured limits at times.The Money market funds are considered Level 1 financial assets. Level 1 financial assets use inputs that are the unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date.

Accounts Receivable

Property and Equipment

Property and Equipment—Property and equipment is stated at cost, less accumulated depreciation. Depreciation is computed on the straight-line method.


Asset Class			Estimated Useful Life
Furniture, fixtures and equipment			5 to 7 years
Leasehold improvements			4 to 6 years

Fair Value of Financial Instruments

Research and Development Costs

Sales and Marketing

General and Administrative

Contributors

Concentration of Credit Risk

Stock-Based Compensation

Restricted Stock Units (RSUs)

Performance-based RSUs

Contingencies

Segment

Leases

Leases—The Company accounts for leases in accordance with ASC 842, Leases, which requires virtually all leases, other than leases that meet the definition of a short-term lease, to be recorded on the balance sheet with a right-of-use (“ROU”) asset and corresponding lease liability. ROU assets are periodically reviewed for impairment whenever events or changes in circumstances arise. During the years ended December 31, 2022, 2021 and 2020, the Company incurred no impairment charges on ROU assets. On the lease commencement date, each lease is classified as either finance or operating, depending on certain criteria. The Company determined that it only has operating leases as none of the criteria for finance lease classification were met. Operating lease expense is recognized on a straight-line basis on the Consolidated Statements of Operations and Comprehensive Loss in General and administrative expenses. On the Consolidated Statements of Changes in Cash Flows, payments for operating leases, are included in operating activities. As an accounting policy election, the Company has elected to not separate lease and non-lease components for all asset classes and made an accounting policy election for short-term leases which does not require the capitalization of leases with terms of 12 months or less at lease commencement. The discount rate utilized in calculating the lease liability is the rate implicit in the lease, if known; otherwise, the incremental borrowing rate (“IBR”) for the expected lease term is used. The Company’s IBR approximates the rate the Company would have to pay, on a collateralized basis, to borrow an amount equal to the lease payments under similar terms.

Impairment of long-lived assets

Recently Issued Pronouncements Not Yet Adopted and Recently Adopted Accounting Pronouncements

Recently Issued Pronouncements Not Yet Adopted

Recently Adopted Accounting Pronouncements

There are no recently adopted accounting pronouncements.

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)

12 Months Ended

Dec. 31, 2022

Accounting Policies [Abstract]

Schedule of Cash and Cash Equivalents

The following table shows the breakout between cash and money market funds.



	December 31, 2022		December 31, 2021
Cash	$	91,189	$	44,165
Money market funds	516,991		509,757
Total	$	608,180	$	553,922

Property, Plant and Equipment


Asset Class			Estimated Useful Life
Furniture, fixtures and equipment			5 to 7 years
Leasehold improvements			4 to 6 years

Property and equipment consists of the following as of December 31, 2022 and December 31, 2021:



	2022		2021
Leasehold improvements	$	15,983	$	10,258
Furniture, fixtures and equipment	5,204		3,053
Total property and equipment	21,187		13,311
Less: accumulated depreciation	(8,218)		(5,100)
Total property and equipment, net	$	12,969	$	8,211

Depreciation expense is included within the following financial statement line items within the Company’s Consolidated Financial Statements.


	Year Ended December 31,
(In thousands)		2022		2021		2020

Research and development		$	1,500	$	260	$	—
Sales and marketing		190		32		—
General and administrative		1,428		1,741		1,624
Total		$	3,118	$	2,033	$	1,624

REVENUE (Tables)

12 Months Ended

Dec. 31, 2022

Revenue from Contract with Customer [Abstract]

Schedule of Revenue Sources and Streams


	Year Ended December 31,
		2022		2021		2020
Revenues:
Subscription		$	273,507	$	180,698	$	117,501
Advertising		44,731		38,501		27,043
Duolingo English Test		32,718		24,658		15,155
Other (1)		18,539		6,915		1,997
Total revenues		$	369,495	$	250,772	$	161,696

________________

(1) Other revenue is mainly comprised of in-app purchases of virtual goods.

Schedule of Revenue by Geographic Areas

Information regarding geography of revenues is based upon the location where the users are located or, in the case of the Duolingo English Test, where the tests are taken:


	Year Ended December 31,
	2022		2021		2020
United States	$	168,320	$	109,163	$	70,978
United Kingdom	31,539		25,163		15,245
Rest of World	169,636		116,446		75,473
Total	$	369,495	$	250,772	$	161,696

Schedule of Deferred Revenues

Changes in deferred revenues were as follows:


	Year Ended December 31,
	2022		2021
Beginning balance—January 1	$	98,267	$	54,792
Amount from beginning balance recognized into revenue	(98,267)		(54,792)
Recognition of deferred revenue	(199,130)		(139,371)
Deferral of revenue	356,680		237,638
Ending balance—December 31	$	157,550	$	98,267

PROPERTY and EQUIPMENT, net (Tables)

12 Months Ended

Dec. 31, 2022

Property, Plant and Equipment [Abstract]

Property, Plant and Equipment


Asset Class			Estimated Useful Life
Furniture, fixtures and equipment			5 to 7 years
Leasehold improvements			4 to 6 years

Property and equipment consists of the following as of December 31, 2022 and December 31, 2021:



	2022		2021
Leasehold improvements	$	15,983	$	10,258
Furniture, fixtures and equipment	5,204		3,053
Total property and equipment	21,187		13,311
Less: accumulated depreciation	(8,218)		(5,100)
Total property and equipment, net	$	12,969	$	8,211

Depreciation expense is included within the following financial statement line items within the Company’s Consolidated Financial Statements.


	Year Ended December 31,
(In thousands)		2022		2021		2020

Research and development		$	1,500	$	260	$	—
Sales and marketing		190		32		—
General and administrative		1,428		1,741		1,624
Total		$	3,118	$	2,033	$	1,624

INTANGIBLE ASSETS AND GOODWILL (Tables)

12 Months Ended

Dec. 31, 2022

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Intangible Assets

Intangible assets consist mostly of capitalized software, with $18 and $0 of other intangible assets as of December 31, 2022 and December 31, 2021, respectively.


	2022		2021
Intangible assets	$	16,827	$	11,144
Less: accumulated amortization	(8,330)		(6,578)
Intangible assets, net	$	8,497	$	4,566

Finite-lived Intangible Assets Amortization Expense

Amortization expense is included within the following financial statement line items within the Company’s Consolidated Financial Statements.


	Year Ended December 31,
(In thousands)		2022		2021		2020
Cost of revenues		$	870	$	—	$	86
Sales and marketing		882		693		546
Total		$	1,752	$	693	$	632

Schedule of Goodwill

Changes in the carrying amount of goodwill are as follows:


(in thousands)	Amount
Balance as of December 31, 2021	$	—
Acquisition	4,050
Balance as of December 31, 2022	$	4,050

- Definition

Tabular disclosure of goodwill by reportable segment and in total which includes a rollforward schedule.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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-Name Accounting Standards Codification
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Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
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-Name Accounting Standards Codification
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-Name Accounting Standards Codification
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Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef
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-Name Accounting Standards Codification
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Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 8: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 9: http://www.xbrl.org/2009/role/commonPracticeRef
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-Name Accounting Standards Codification
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-URI https://asc.fasb.org/extlink&oid=121556970&loc=d3e13816-109267

Reference 10: http://www.xbrl.org/2009/role/commonPracticeRef
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-Paragraph 2
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-URI https://asc.fasb.org/extlink&oid=121556970&loc=d3e13854-109267

Reference 11: http://www.xbrl.org/2003/role/exampleRef
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-Name Accounting Standards Codification
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-URI https://asc.fasb.org/extlink&oid=122137925&loc=d3e14258-109268

Reference 12: http://www.xbrl.org/2009/role/commonPracticeRef
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-URI https://asc.fasb.org/extlink&oid=121556970&loc=d3e13816-109267

+ Details

LEASES (Tables)

12 Months Ended

Dec. 31, 2022

Leases [Abstract]

Summary of Components of Lease Cost

The following represents the components of lease cost for the years ended December 31, 2022, 2021 and 2020 along with supplemental disclosures of cash flow information, lease term and discount rate:


	Year Ended December 31,
	2022			2021			2020
Operating lease cost	$	7,076		$	1,919		$	1,721
Short term lease cost	125			1,266			317
Variable lease cost	63			28			—
Total lease cost	$	7,264		$	3,213		$	2,038

Cash paid for amounts included in the measurement of lease liabilities	$	5,168		$	1,819		$	—
Right-of-use assets obtained in exchange for new operating lease liabilities	$	909		$	22,274		$	—
Right of use assets disposed or adjusted, modifying operating leases liabilities	$	(1,586)		$	(235)		$	—
Gain from termination of leases	$	—		$	31		$	—
Weighted-average remaining lease term	9 years			9 years			8 years, 11 months
Weighted-average discount rate	6.92		%	5.77		%	6.70		%

Schedule of Future Minimum Rental Payments for Operating Leases

The following table reconciles future minimum undiscounted rental commitments for operating leases to operating lease liabilities recorded on the Consolidated Balance Sheet as of December 31, 2022:


Fiscal year
2023	$	6,719
2024	4,702
2025	3,239
2026	3,310
2027	3,371
Thereafter	18,834
Total undiscounted lease payments	$	40,175
Present value adjustment	(11,769)
Operating lease liabilities	$	28,406

INCOME TAXES (Tables)

12 Months Ended

Dec. 31, 2022

Income Tax Disclosure [Abstract]

Schedule of Components of Income Tax Expense (Benefit)

For the years ended December 31, 2022, 2021 and 2020 the Company recognized the following provision for income taxes:


	Year Ended December 31,
	2022		2021		2020
Current:
Federal	$	302	$	—	$	—
State	327		80		42
Foreign	524		97		26
Total	$	1,153	$	177	$	68

Deferred:
Federal	$	—	$	—	$	—
State	—		—		—
Foreign	(215)		—		—
Total	$	(215)	$	—	$	—

Total provision for income taxes	$	938	$	177	$	68

Schedule of Effective Income Tax Rate Reconciliation

The provision for income taxes differs from the amounts computed by applying the federal statutory rate as follows for the years ended December 31, 2022, 2021 and 2020:


	2022		2021		2020
Federal statutory rate	21.0	%	21.0	%	21.0	%
State taxes	6.7		6.5		1.8
Section 162(m) limitation	(15.2)		(13.5)		—
Equity compensation	28.4		53.8		(18.4)
Other permanent adjustments	(0.9)		(0.5)		(1.8)
Research and development credit	11.7		15.9		10.2
Valuation allowance	(53.3)		(83.5)		(13.2)
Effective income tax rate	(1.6)	%	(0.3)	%	(0.4)	%

Schedule of Deferred Tax Assets and Liabilities

The Company has the following deferred tax assets (liabilities) as of December 31, 2022 and 2021:


	2022		2021
Net operating loss carryforwards	$	42,861	$	61,605
Equity compensation	3,605		1,881
Research and development credits	22,386		14,480
Lease liability	6,487		7,335
Section 174 research and development capitalization	42,429		—
Marketing and advertising	633		—
Sales tax / Value added tax ("VAT") reserve	210		277
Other deferred tax assets	140		56
Valuation allowance	(108,504)		(76,293)
Total deferred tax assets	10,247		9,341

ROU asset	(5,122)		(6,389)
Property and equipment	(2,569)		(1,894)
Capitalized software	(1,913)		(1,057)
Other deferred tax liabilities	(10)		(1)
Total deferred tax liabilities	(9,614)		(9,341)

Net deferred taxes	$	633	$	—

Summary of Valuation Allowance

The following table represents the activity in our valuation allowance for the years ended December 31, 2022 and 2021:


	Year Ended December 31,
	2022		2021
Beginning balance—January 1	$	(76,293)	$	(26,236)
Valuation allowances established	(32,211)		(50,057)
Release of valuation allowances	—		—
Ending balance—December 31	$	(108,504)	$	(76,293)

CONVERTIBLE PREFERRED STOCK (Tables)

12 Months Ended

Dec. 31, 2022

Temporary Equity Disclosure [Abstract]

Temporary Equity

The following table summarizes the convertible preferred stock outstanding immediately prior to the conversion into common stock and as of December 31, 2020:


	Shares
Series	Authorized	Outstanding	Per share price at issuance		Aggregate liquidation preference		Funds received		Fees incurred		Carrying value of convertible preferred stock
A	3,865	3,865	$	0.85	$	3,300	$	3,300	$	52	$	3,248
B	6,298	6,298	2.38		$	15,000	$	15,000	$	60	$	14,940
C	2,948	2,948	6.78		$	20,000	$	20,000	$	112	$	19,888
D	3,154	3,154	14.27		$	45,000	$	45,000	$	146	$	44,853
E	1,224	1,224	20.43		$	25,000	$	25,000	$	92	$	24,909
F	758	758	39.57		$	30,000	$	30,000	$	153	$	29,848
G	241	241	41.38		$	10,000	$	10,000	$	24	$	9,976
H	586	586	59.77		$	35,000	$	35,000	$	52	$	34,947
Total	19,074	19,074			$	183,300	$	183,300	$	691	$	182,609

STOCK-BASED COMPENSATION (Tables)

12 Months Ended

Dec. 31, 2022

Equity [Abstract]

Share-based Payment Arrangement, Option, Activity

A summary of stock option activity under the Plans was as follows:


	Number of options	Weighted- average exercise price		Weighted- average remaining contractual life (years)	Aggregate intrinsic value





Options outstanding at January 1, 2022	6,255	$	12.53	6.92	$	585,339
Granted (1)	—
Exercised	(1,739)	8.47
Repurchased	—
Forfeited and expired	(106)	16.47
Options outstanding at December 31, 2022	4,410	$	14.04	6.25	$	251,832
Options exercisable at December 31, 2022	3,689	$	13.08	6.03	$	214,131

________________

(1) There were no stock options granted during the year ended December 31, 2022

Share-based Payment Arrangement, Option, Valuation Assumptions

The fair value of each option grant is estimated on the date of grant using the Black-Scholes option pricing model with the following assumptions:

2022

2021

2020

Risk-free interest rate

n/a

1.04 – 1.14%

0.32 – 0.68%

Expected life

n/a

5.90 years

6.01 years

Expected volatility

n/a

48.90 – 49.12%

45.50 – 49.38%

Dividend yield

n/a

—%

Fair value of common stock

n/a

$38.08 – $52.80

$14.42 – $38.08

Share-based Payment Arrangement, RSU, Activity


	Restricted stock units	Weighted- average grant date fair value per share




Outstanding at January 1, 2022	730	$	77.09
Granted	1,755	88.56
Released	(350)	82.26
Forfeited	(99)	84.30
Outstanding at December 31, 2022	2,036	$	85.74

Share-based Payment Arrangement, Payment Award


Tranche	Company Stock Price Hurdle		Number of RSUs Eligible to Vest
1	$	127.50	90
2	$	153.00	90
3	$	178.50	90
4	$	204.00	180
5	$	255.00	180
6	$	306.00	180
7	$	357.00	180
8	$	408.00	180
9	$	612.00	270
10	$	816.00	360

The weighted-average grant date fair value of the Founder Awards was estimated to be $61.56 per share using the below inputs.


Input			Assumption
Valuation Date			June 28, 2021
Risk-free interest rate			1.48%
Expected life			9.98
Expected volatility			51.67%
Dividend yield			0.00%
Fair value of common stock			$95.00

Share-based Payment Arrangement, Expensed, Amount

Stock based compensation expense is included in the Consolidated Statements of Operations and Comprehensive Loss as shown in the following table:


	Year Ended December 31,
		2022		2021		2020
Cost of revenues		$	38	$	8	$	6
Research and development		26,373		9,298		2,773
Sales and marketing		2,540		881		348
General and administrative		44,869		30,617		13,904
Total		$	73,820	$	40,804	$	17,031

ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES (Tables)

12 Months Ended

Dec. 31, 2022

Other Liabilities Disclosure [Abstract]

Schedule of Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consisted of the following:


	December 31, 2022		December 31, 2021
Obligations under current leases	$	4,903	$	3,336
Employee-related costs	4,233		2,075
Marketing related accruals	3,464		1,078
Sales and VAT tax accrual	2,396		2,319
Other	6,974		4,125
Total	$	21,970	$	12,933

LOSS PER SHARE (Tables)

12 Months Ended

Dec. 31, 2022

Earnings Per Share [Abstract]

Schedule of Earnings Per Share, Basic and Diluted

The diluted net loss per share attributable to common stockholders is calculated by giving effect to all potential dilutive common stock equivalents outstanding for the period.


	Year Ended December 31,
(In thousands, except per share data)		2022		2021		2020
Numerator:
Net loss attributable to Class A and Class B common stockholders		$	(59,574)	$	(60,135)	(15,776)


Denominator:
Weighted-average shares in computing net loss per share attributable to Class A and Class B common stockholders, basic and diluted		39,470		23,433		12,735




Basic loss per common share		$	(1.51)	$	(2.57)	$	(1.24)
Diluted loss per common share		$	(1.51)	$	(2.57)	$	(1.24)

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share

The potential shares of common stock that were excluded from the computation of diluted net loss per share attributable to common stockholders for the period presented because including them would have been antidilutive are as follows:


	Year Ended December 31,
(in thousands)	2022	2021	2020
Convertible preferred stock	—	—	19,074
Founder awards where performance has been met	180	180	—
Stock options outstanding (1)	4,410	6,255	8,365
RSUs outstanding (1)	2,036	730	34
Total	6,626	7,165	27,473

________________

(1) Prior year amounts were adjusted in the current year table to include unvested options and RSUs

DESCRIPTION OF THE BUSINESS AND BASIS OF PRESENTATION (Details) $ / shares in Units, $ in Thousands		12 Months Ended
	Jul. 30, 2021 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) language shares	Dec. 31, 2021 USD ($) shares	Dec. 31, 2020 USD ($)	Jul. 29, 2021 USD ($)	Jul. 15, 2021 shares
Business And Organization [Line Items]
Issuance of common stock in connection with the initial public offering, net of underwriting discounts and issuance costs \| $	$ 455,532	$ 0	$ 426,191	$ 0
Common stock carrying value \| $		$ 4	$ 4
Number of languages, more than \| language		40
Common Class A
Business And Organization [Line Items]
Common stock, shares outstanding (in shares)		31,899,000	16,645,000
Common Class A \| IPO
Business And Organization [Line Items]
Sale of stock, number of shares issued in transaction (in shares)	5,872,000
Sale of stock, price per share (in usd per share) \| $ / shares	$ 102.00
Common Class A \| IPO \| Stockholders
Business And Organization [Line Items]
Sale of stock, number of shares issued in transaction (in shares)	1,406,000
Common Class A \| IPO \| Duolingo
Business And Organization [Line Items]
Sale of stock, number of shares issued in transaction (in shares)	4,466,000
Common Class A \| Over-Allotment Option
Business And Organization [Line Items]
Sale of stock, number of shares issued in transaction (in shares)	766,000
Common Class B
Business And Organization [Line Items]
Conversion ratio					1
Common stock carrying value \| $					$ 182,609
Common stock, shares outstanding (in shares)		8,462,000	21,627
Common Class B \| Founders
Business And Organization [Line Items]
Common stock, shares outstanding (in shares)						6,930,000

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Cash and Cash Equivalents (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	$ 608,180	$ 553,922
Cash
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	91,189	44,165
Money market funds
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	$ 516,991	$ 509,757

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details) shares in Thousands			1 Months Ended	3 Months Ended	12 Months Ended
	Jul. 30, 2021 USD ($)	Mar. 10, 2021 USD ($)	Jun. 30, 2021 shares	Mar. 31, 2022	Dec. 31, 2022 USD ($) tranche reporting_unit shares	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Concentration Risk [Line Items]
Number of days to take exam					21 days
Advertising costs					$ 48,111,000	$ 42,964,000	$ 27,352,000
Volunteer program, one-time payment to contributors		$ 4,220,000
Volunteer program, fees paid		$ 526,000
Compensation expense					$ 73,820,000	40,804,000	17,031,000
Number of reporting units \| reporting_unit					1
Impairment					$ 0	0	0
Research and development
Concentration Risk [Line Items]
Compensation expense					26,373,000	9,298,000	2,773,000
Sales and marketing
Concentration Risk [Line Items]
Compensation expense					2,540,000	881,000	348,000
General and administrative
Concentration Risk [Line Items]
Compensation expense					$ 44,869,000	30,617,000	$ 13,904,000
RSUs outstanding
Concentration Risk [Line Items]
Number of vesting requirements \| tranche					2
Vesting period (in years)					4 years
Compensation expense	$ 2,035,000					2,035,000
Equity instruments other than options, grants in period (in shares) \| shares					1,755
RSUs outstanding \| Research and development
Concentration Risk [Line Items]
Compensation expense						1,332,000
RSUs outstanding \| Sales and marketing
Concentration Risk [Line Items]
Compensation expense						210,000
RSUs outstanding \| General and administrative
Concentration Risk [Line Items]
Compensation expense						493,000
Founder awards where performance has been met \| 1
Concentration Risk [Line Items]
Compensation expense					$ 30,997,000	$ 16,463,000
Founder awards where performance has been met \| Founders
Concentration Risk [Line Items]
Equity instruments other than options, grants in period (in shares) \| shares			1,800
Number of tranches \| tranche					10
Capitalized Software
Concentration Risk [Line Items]
Estimated useful life (in years)					3 years
Accounts Receivable \| Customer Concentration Risk \| Apple
Concentration Risk [Line Items]
Concentration risk, percentage				51.10%	56.20%
Accounts Receivable \| Customer Concentration Risk \| Google
Concentration Risk [Line Items]
Concentration risk, percentage				27.90%	27.50%
Accounts Receivable \| Customer Concentration Risk \| Stripe
Concentration Risk [Line Items]
Concentration risk, percentage				10.10%
Revenue Benchmark \| Customer Concentration Risk \| Apple
Concentration Risk [Line Items]
Concentration risk, percentage					54.20%	50.50%	51.30%
Revenue Benchmark \| Customer Concentration Risk \| Google
Concentration Risk [Line Items]
Concentration risk, percentage					28.10%	29.00%	26.90%
Revenue Benchmark \| Customer Concentration Risk \| Stripe
Concentration Risk [Line Items]
Concentration risk, percentage						10.10%

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Useful Life (Details)	12 Months Ended
	Dec. 31, 2022
Furniture, fixtures and equipment \| Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Life (in years)	5 years
Furniture, fixtures and equipment \| Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful Life (in years)	7 years
Leasehold improvements \| Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Life (in years)	4 years
Leasehold improvements \| Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful Life (in years)	6 years

ACQUISITION (Details) $ in Thousands		12 Months Ended
ACQUISITION (Details) $ in Thousands	Oct. 03, 2022 USD ($) employee term	Dec. 31, 2022 USD ($)
Asset Acquisition [Line Items]
Sublease term (in months)	68 months
Sublease payments to be received		$ 358
Total undiscounted lease payments		40,175
Office space
Asset Acquisition [Line Items]
Lessee, operating lease, term of contract (in months)	68 months
Total undiscounted lease payments		$ 750
Office space \| Office Lease, Five Year Renewal Term
Asset Acquisition [Line Items]
Number of extension options \| term	1
Option to extend (in years)	5 years
Office space \| Office Lease, Four Year Renewal Term
Asset Acquisition [Line Items]
Number of extension options \| term	1
Option to extend (in years)	4 years
Gunner Made LLC
Asset Acquisition [Line Items]
Number of design team members \| employee	15
Asset acquisition, consideration transferred	$ 4,500
Cash paid in asset acquisition	4,000
Asset acquisition, amount held back until one year of continued service	$ 450
Continued service period (in years)		1 year
Acquisition costs		$ 50

REVENUE - Narrative (Details)	12 Months Ended
REVENUE - Narrative (Details)	Dec. 31, 2022 sourceOfRevenue user	Dec. 31, 2021	Dec. 31, 2020
Disaggregation of Revenue [Line Items]
Number of sources of revenue \| sourceOfRevenue	3
Number of users \| user	6
Number of hours to make certification decision	48 hours
Number of days to take exam	21 days
Expiration period to take exams	1 year
United States \| Revenue from Contract with Customer Benchmark \| Geographic Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration risk, percentage	46.00%	44.00%	44.00%
United Kingdom \| Revenue from Contract with Customer Benchmark \| Geographic Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration risk, percentage	9.00%	10.00%	9.00%
Minimum
Disaggregation of Revenue [Line Items]
Subscription period	6 months
Maximum
Disaggregation of Revenue [Line Items]
Subscription period	1 year

REVENUE - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, excluding assessed tax	$ 369,495	$ 250,772	$ 161,696
Transferred over Time \| Subscription
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, excluding assessed tax	273,507	180,698	117,501
Transferred over Time \| Advertising
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, excluding assessed tax	44,731	38,501	27,043
Transferred over Time \| Duolingo English Test
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, excluding assessed tax	32,718	24,658	15,155
Transferred over Time \| Other
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, excluding assessed tax	$ 18,539	$ 6,915	$ 1,997

- Definition

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 30
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8906-108599

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 40
-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e9031-108599

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 41
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e9038-108599

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8933-108599

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-Name Accounting Standards Codification
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-Paragraph 32
-Subparagraph (a)
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Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126920106&loc=SL49130543-203045

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
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-Paragraph 22
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8736-108599

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
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-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e9054-108599

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI https://asc.fasb.org/extlink&oid=126920106&loc=SL49130545-203045

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 924
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 11.L)
-URI https://asc.fasb.org/extlink&oid=6472922&loc=d3e499488-122856

+ Details

REVENUE - Revenue by Geographic Area (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Disaggregation of Revenue [Line Items]
Revenues	$ 369,495	$ 250,772	$ 161,696
United States
Disaggregation of Revenue [Line Items]
Revenues	168,320	109,163	70,978
United Kingdom
Disaggregation of Revenue [Line Items]
Revenues	31,539	25,163	15,245
Rest of World
Disaggregation of Revenue [Line Items]
Revenues	$ 169,636	$ 116,446	$ 75,473

- Definition

+ References

+ Details

REVENUE - Deferred Revenue Rollforward (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Revenue from Contract with Customer, Liability [Roll Forward]
Beginning balance	$ 98,267	$ 54,792
Amount from beginning balance recognized into revenue	(98,267)	(54,792)
Recognition of deferred revenue	(199,130)	(139,371)
Deferral of revenue	356,680	237,638
Ending balance	$ 157,550	$ 98,267

PROPERTY and EQUIPMENT, net - Summary (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 21,187	$ 13,311
Less: accumulated depreciation	(8,218)	(5,100)
Total property and equipment, net	12,969	8,211
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total property and equipment	15,983	10,258
Furniture, fixtures and equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 5,204	$ 3,053

PROPERTY and EQUIPMENT, net - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 3,118	$ 2,033	$ 1,624

PROPERTY and EQUIPMENT, net - Summary of Depreciation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Total	$ 3,118	$ 2,033	$ 1,624
Research and development
Property, Plant and Equipment [Line Items]
Total	1,500	260	0
Sales and marketing
Property, Plant and Equipment [Line Items]
Total	190	32	0
General and administrative
Property, Plant and Equipment [Line Items]
Total	$ 1,428	$ 1,741	$ 1,624

INTANGIBLE ASSETS AND GOODWILL - Capitalized Software (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible assets	$ 16,827	$ 11,144
Less: accumulated amortization	(8,330)	(6,578)
Intangible assets, net	$ 8,497	$ 4,566

INTANGIBLE ASSETS AND GOODWILL - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Other intangible assets	$ 18,000	$ 0
Capitalized software development costs	5,665,000	2,963,000
Amortization of capitalized computer software	1,752,000	$ 693,000	$ 632,000
Goodwill, tax deductible amount	$ 3,983,000

INTANGIBLE ASSETS AND GOODWILL - Schedule of Capitalized Software Amortization Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Amortization of capitalized computer software	$ 1,752	$ 693	$ 632
Cost of revenues
Finite-Lived Intangible Assets [Line Items]
Amortization of capitalized computer software	870	0	86
Sales and marketing
Finite-Lived Intangible Assets [Line Items]
Amortization of capitalized computer software	$ 882	$ 693	$ 546

INTANGIBLE ASSETS AND GOODWILL - Schedule of Goodwill (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($)
Goodwill [Roll Forward]
Balance as of December 31, 2021	$ 0
Acquisition	4,050
Balance as of December 31, 2022	$ 4,050

- Definition

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References + Details

LEASES - Narrative (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Lessee, Lease, Description [Line Items]
Renewal term (in years)	5 years
Obligations under current leases	$ 4,903	$ 3,336
Operating lease, liability, current, statement of financial position, [extensible enumeration]	Accrued expenses and other current liabilities	Accrued expenses and other current liabilities
Operating lease liability, noncurrent	$ 23,503	$ 29,124
Obligation
Lessee, Lease, Description [Line Items]
Operating lease liability, noncurrent	$ 23,503	$ 29,124

LEASES - Components of Lease Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Leases [Abstract]
Operating lease cost	$ 7,076	$ 1,919	$ 1,721
Short term lease cost	125	1,266	317
Variable lease cost	63	28	0
Total lease cost	7,264	3,213	2,038
Cash paid for amounts included in the measurement of lease liabilities	5,168	1,819	0
Right-of-use assets obtained in exchange for new operating lease liabilities	909	22,274	0
Right of use assets disposed or adjusted, modifying operating leases liabilities	(1,586)	(235)	0
Gain from termination of leases	$ 0	$ 31	$ 0
Weighted-average remaining lease term	9 years	9 years	8 years 11 months
Weighted-average discount rate	6.92%	5.77%	6.70%

LEASES - Future Minimum Rental Payment (Details) $ in Thousands	Dec. 31, 2022 USD ($)
Leases [Abstract]
2023	$ 6,719
2024	4,702
2025	3,239
2026	3,310
2027	3,371
Thereafter	18,834
Total undiscounted lease payments	40,175
Present value adjustment	(11,769)
Operating lease liabilities	$ 28,406

INCOME TAXES - Provision of Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Current:
Federal	$ 302	$ 0	$ 0
State	327	80	42
Foreign	524	97	26
Total	1,153	177	68
Deferred:
Federal	0	0	0
State	0	0	0
Foreign	(215)	0	0
Total	(215)	0	0
Provision for income taxes	$ 938	$ 177	$ 68

INCOME TAXES - Effective Income Tax Rate Reconciliation (Details)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Federal statutory rate	21.00%	21.00%	21.00%
State taxes	6.70%	6.50%	1.80%
Section 162(m) limitation	(15.20%)	(13.50%)	0.00%
Equity compensation	28.40%	53.80%	(18.40%)
Other permanent adjustments	(0.90%)	(0.50%)	(1.80%)
Research and development credit	11.70%	15.90%	10.20%
Valuation allowance	(53.30%)	(83.50%)	(13.20%)
Effective income tax rate	(1.60%)	(0.30%)	(0.40%)

INCOME TAXES - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Net operating loss carryforwards	$ 42,861	$ 61,605
Equity compensation	3,605	1,881
Research and development credits	22,386	14,480
Lease liability	6,487	7,335
Section 174 research and development capitalization	42,429	0
Marketing and advertising	633	0
Sales tax / Value added tax ("VAT") reserve	210	277
Other deferred tax assets	140	56
Valuation allowance	(108,504)	(76,293)	$ (26,236)
Total deferred tax assets	10,247	9,341
ROU asset	(5,122)	(6,389)
Property and equipment	(2,569)	(1,894)
Capitalized software	(1,913)	(1,057)
Other deferred tax liabilities	(10)	(1)
Total deferred tax liabilities	(9,614)	(9,341)
Net deferred taxes	$ 633	$ 0

INCOME TAXES - Narrative (Details) - USD ($)	12 Months Ended
INCOME TAXES - Narrative (Details) - USD ($)	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating Loss Carryforwards [Line Items]
Decrease in valuation allowance	$ 32,211,000
Unrecognized tax benefits	0	$ 0	$ 0
General Business Tax Credit Carryforward
Operating Loss Carryforwards [Line Items]
Business credits	22,387,000
Federal
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	172,046,000
State
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	$ 86,164,000

INCOME TAXES - Valuation Allowance (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Beginning balance	$ (76,293)	$ (26,236)
Valuation allowances established	(32,211)	(50,057)
Release of valuation allowances	0	0
Ending balance	$ (108,504)	$ (76,293)

CONVERTIBLE PREFERRED STOCK - Schedule of Convertible Preferred Stock (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Jul. 29, 2021	Dec. 31, 2020	Dec. 31, 2019
Temporary Equity [Line Items]
Authorized (in shares)			19,074	19,074
Outstanding (in shares)	0	0	19,074	19,074	18,247
Aggregate liquidation preference			$ 183,300	$ 183,300
Funds received			183,300	183,300
Fees incurred			691	691
Carrying value of convertible preferred stock	$ 0	$ 0	$ 182,609	$ 182,609	$ 137,686
A
Temporary Equity [Line Items]
Authorized (in shares)			3,865	3,865
Outstanding (in shares)			3,865	3,865
Per share price at issuance (in usd per share)			$ 0.85	$ 0.85
Aggregate liquidation preference			$ 3,300	$ 3,300
Funds received			3,300	3,300
Fees incurred			52	52
Carrying value of convertible preferred stock			$ 3,248	$ 3,248
B
Temporary Equity [Line Items]
Authorized (in shares)			6,298	6,298
Outstanding (in shares)			6,298	6,298
Per share price at issuance (in usd per share)			$ 2.38	$ 2.38
Aggregate liquidation preference			$ 15,000	$ 15,000
Funds received			15,000	15,000
Fees incurred			60	60
Carrying value of convertible preferred stock			$ 14,940	$ 14,940
C
Temporary Equity [Line Items]
Authorized (in shares)			2,948	2,948
Outstanding (in shares)			2,948	2,948
Per share price at issuance (in usd per share)			$ 6.78	$ 6.78
Aggregate liquidation preference			$ 20,000	$ 20,000
Funds received			20,000	20,000
Fees incurred			112	112
Carrying value of convertible preferred stock			$ 19,888	$ 19,888
D
Temporary Equity [Line Items]
Authorized (in shares)			3,154	3,154
Outstanding (in shares)			3,154	3,154
Per share price at issuance (in usd per share)			$ 14.27	$ 14.27
Aggregate liquidation preference			$ 45,000	$ 45,000
Funds received			45,000	45,000
Fees incurred			146	146
Carrying value of convertible preferred stock			$ 44,853	$ 44,853
E
Temporary Equity [Line Items]
Authorized (in shares)			1,224	1,224
Outstanding (in shares)			1,224	1,224
Per share price at issuance (in usd per share)			$ 20.43	$ 20.43
Aggregate liquidation preference			$ 25,000	$ 25,000
Funds received			25,000	25,000
Fees incurred			92	92
Carrying value of convertible preferred stock			$ 24,909	$ 24,909
F
Temporary Equity [Line Items]
Authorized (in shares)			758	758
Outstanding (in shares)			758	758
Per share price at issuance (in usd per share)			$ 39.57	$ 39.57
Aggregate liquidation preference			$ 30,000	$ 30,000
Funds received			30,000	30,000
Fees incurred			153	153
Carrying value of convertible preferred stock			$ 29,848	$ 29,848
G
Temporary Equity [Line Items]
Authorized (in shares)			241	241
Outstanding (in shares)			241	241
Per share price at issuance (in usd per share)			$ 41.38	$ 41.38
Aggregate liquidation preference			$ 10,000	$ 10,000
Funds received			10,000	10,000
Fees incurred			24	24
Carrying value of convertible preferred stock			$ 9,976	$ 9,976
H
Temporary Equity [Line Items]
Authorized (in shares)			586	586
Outstanding (in shares)			586	586
Per share price at issuance (in usd per share)			$ 59.77	$ 59.77
Aggregate liquidation preference			$ 35,000	$ 35,000
Funds received			35,000	35,000
Fees incurred			52	52
Carrying value of convertible preferred stock			$ 34,947	$ 34,947

CONVERTIBLE PREFERRED STOCK - Narrative (Details) shares in Thousands, $ in Thousands	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Jul. 29, 2021 USD ($) shares
Temporary Equity [Line Items]
Common stock carrying value	$ 4	$ 4
Common Class B
Temporary Equity [Line Items]
Convertible preferred stock, shares issued upon conversion (in shares) \| shares			19,074
Conversion ratio			1
Common stock carrying value			$ 182,609

STOCK-BASED COMPENSATION - Narrative (Details) $ / shares in Units, shares in Thousands, $ in Thousands				1 Months Ended		12 Months Ended
	Jan. 01, 2023 shares	Jan. 01, 2022 shares	Jul. 30, 2021 USD ($) $ / shares	Jun. 30, 2021 shares	Feb. 28, 2021 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) tranche day $ / shares shares	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Jul. 26, 2021 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate intrinsic value, exercised						$ 140,884	$ 194,513	$ 6,058
Compensation expense						73,820	40,804	17,031
Unrecognized compensation cost, options						5,663
Unrecognized compensation cost						$ 169,387
Closing trading price, specified calendar \| day						60
Fair market value of share price (in usd per share) \| $ / shares					$ 38.08
Payments for repurchase of stock options						$ 0	7,335	$ 0
Options repurchased							(7,335)
Common stock repurchased and retired							868
Additional Paid-In Capital
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options repurchased							(7,335)
Common stock repurchased and retired							868
Tender Offer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense					$ 5,275
Sale Of Stock, Percentage Sold, Maximum					0.10
Sale of stock, price per share (in usd per share) \| $ / shares					$ 59.77
Payments for repurchase of stock options					$ 13,479
Stock returned during the period (in shares) \| shares					220
Common stock repurchased and retired (in shares) \| shares					23
Common stock repurchased and retired					$ 868
Tender Offer \| Additional Paid-In Capital
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options repurchased					$ 7,335
Common Class A \| IPO
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Sale of stock, price per share (in usd per share) \| $ / shares			$ 102.00
Stock options outstanding
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost, weighted-average period of recognition (in years)						1 year
Number of options available for grant (in shares) \| shares						8,117
RSUs outstanding
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)						4 years
Compensation expense			$ 2,035				2,035
Unrecognized compensation cost, weighted-average period of recognition (in years)						3 years
Unrecognized compensation expense, excluding options						$ 163,724
Equity instruments other than options, grants in period (in shares) \| shares						1,755
Performance Based RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense, excluding options						$ 63,357
Performance Based RSUs \| Share-Based Payment Arrangement, Founders
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value (in usd per share) \| $ / shares						$ 61.56
Performance Based RSUs \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award service period						3 years 6 months 29 days
Performance Based RSUs \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award service period						5 years 11 months 1 day
Performance Based RSUs \| Tranche One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense						$ 30,997	16,463
Performance Based RSUs \| Tranche One \| IPO
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense							$ 5,574
Performance Based RSUs \| Founders
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense, excluding options						$ 110,817
Equity instruments other than options, grants in period (in shares) \| shares				1,800
Settlement period after vesting				1 year
Award vesting percentage				25.00%
Number of tranches \| tranche						10
Award service period				10 years
Performance Based RSUs \| Founders \| Tranche One and Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of tranches \| tranche						2
2021 Plan \| Common Class A
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance (in shares) \| shares		1,913							7,946
Share-based compensation, shares outstanding increase, maximum amount (in percent)		5.00%
2021 Plan \| Common Class A \| Subsequent Event
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Additional shares authorized (in shares) \| shares	2,018
Employee Stock Purchase Plan \| Common Class A
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance (in shares) \| shares		166							1,119
Employee Stock Purchase Plan \| Common Class A \| Subsequent Event
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Additional shares authorized (in shares) \| shares	319
2011 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)						4 years
Share-based compensation, term of award						10 years

STOCK-BASED COMPENSATION - Stock Option Activity (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Number of options
Options outstanding, beginning balance (in shares)	6,255
Granted (in shares)	0
Exercised (in shares)	(1,739)
Repurchased (in shares)	0
Forfeited and expired (in shares)	(106)
Options outstanding, ending balance (in shares)	4,410	6,255
Number of options exercisable (in shares)	3,689
Weighted- average exercise price
Outstanding, beginning balance (in usd per share)	$ 12.53
Granted (in usd per share)
Exercised (in usd per share)	8.47
Repurchased (in usd per share)
Forfeited and expired (in usd per share)	16.47
Outstanding, ending balance (in usd per share)	14.04	$ 12.53
Weighted average exercise price, options exercisable (in usd per share)	$ 13.08
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Weighted average remaining contractual term (in years), outstanding	6 years 3 months	6 years 11 months 1 day
Weighted average remaining contractual term (in years), exercisable	6 years 10 days
Aggregate intrinsic value, outstanding	$ 251,832	$ 585,339
Aggregate intrinsic value, exercisable	$ 214,131

STOCK-BASED COMPENSATION - Schedule of Payment Pricing Model (Details) - $ / shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate, minimum	1.04%	0.32%
Risk-free interest rate, maximum	1.14%	0.68%
Expected life	5 years 10 months 24 days	6 years 3 days
Expected volatility, minimum	48.90%	45.50%
Expected volatility, maximum	49.12%	49.38%
Dividend yield	0.00%	0.00%
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of common stock (in usd per share)	$ 38.08	$ 14.42
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of common stock (in usd per share)	$ 52.80	$ 38.08

STOCK-BASED COMPENSATION - Schedule of Restricted Stock Unit Activity (Details) - RSUs outstanding - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Restricted stock units
Beginning balance (in shares)	2,036	730
Granted (in shares)	1,755
Released (in shares)	(350)
Forfeited (in shares)	(99)
Ending balance (in shares)	2,036
Weighted- average grant date fair value per share
Beginning balance (in usd per share)	$ 77.09
Granted (in usd per share)	88.56
Released (in usd per share)	82.26
Forfeited (in usd per share)	84.30
Ending balance (in usd per share)	$ 85.74

STOCK-BASED COMPENSATION - Schedule of Payment Award (Details) - RSUs outstanding shares in Thousands	Dec. 31, 2022 $ / shares shares
1
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Company Stock Price Hurdle (in usd per share) \| $ / shares	$ 127.50
Number of RSUs Eligible to Vest (in shares) \| shares	90
2
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Company Stock Price Hurdle (in usd per share) \| $ / shares	$ 153.00
Number of RSUs Eligible to Vest (in shares) \| shares	90
3
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Company Stock Price Hurdle (in usd per share) \| $ / shares	$ 178.50
Number of RSUs Eligible to Vest (in shares) \| shares	90
4
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Company Stock Price Hurdle (in usd per share) \| $ / shares	$ 204.00
Number of RSUs Eligible to Vest (in shares) \| shares	180
5
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Company Stock Price Hurdle (in usd per share) \| $ / shares	$ 255.00
Number of RSUs Eligible to Vest (in shares) \| shares	180
6
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Company Stock Price Hurdle (in usd per share) \| $ / shares	$ 306.00
Number of RSUs Eligible to Vest (in shares) \| shares	180
7
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Company Stock Price Hurdle (in usd per share) \| $ / shares	$ 357.00
Number of RSUs Eligible to Vest (in shares) \| shares	180
8
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Company Stock Price Hurdle (in usd per share) \| $ / shares	$ 408.00
Number of RSUs Eligible to Vest (in shares) \| shares	180
9
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Company Stock Price Hurdle (in usd per share) \| $ / shares	$ 612.00
Number of RSUs Eligible to Vest (in shares) \| shares	270
10
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Company Stock Price Hurdle (in usd per share) \| $ / shares	$ 816.00
Number of RSUs Eligible to Vest (in shares) \| shares	360

STOCK-BASED COMPENSATION - Schedule of Weighted Average Pricing Model (Details) - $ / shares		12 Months Ended
	Jun. 28, 2021	Dec. 31, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life		5 years 10 months 24 days	6 years 3 days
Dividend yield		0.00%	0.00%
Founder awards where performance has been met
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	1.48%
Expected life	9 years 11 months 23 days
Expected volatility	51.67%
Dividend yield	0.00%
Fair value of common stock (in usd per share)	$ 95.00

STOCK-BASED COMPENSATION - Schedule of Income Statement Location for Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	$ 73,820	$ 40,804	$ 17,031
Cost of revenues
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	38	8	6
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	26,373	9,298	2,773
Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	2,540	881	348
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	$ 44,869	$ 30,617	$ 13,904

ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Other Liabilities Disclosure [Abstract]
Obligations under current leases	$ 4,903	$ 3,336
Employee-related costs	4,233	2,075
Marketing related accruals	3,464	1,078
Sales and VAT tax accrual	2,396	2,319
Other	6,974	4,125
Total	$ 21,970	$ 12,933

EMPLOYEE BENEFIT PLAN (Details) - USD ($)	12 Months Ended
EMPLOYEE BENEFIT PLAN (Details) - USD ($)	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, contributions by employer	$ 4,624,000	$ 3,438,000	$ 1,796,000
Defined contribution plan, employer discretionary contribution amount	$ 0	$ 0	$ 0
First 4% of Employee Elective Deferral
Defined Benefit Plan Disclosure [Line Items]
Employer matching contribution, percent of match (in percent)	100.00%		100.00%
Employer matching contribution, percent of employees' gross pay (in percent)	4.00%		3.00%
Next 2% of Employee Elective Deferral
Defined Benefit Plan Disclosure [Line Items]
Employer matching contribution, percent of match (in percent)	50.00%		50.00%
Employer matching contribution, percent of employees' gross pay (in percent)	2.00%		2.00%

LOSS PER SHARE - Schedule of Earnings Per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Numerator:
Net loss	$ (59,574)	$ (60,135)	$ (15,776)
Denominator:
Weighted-average shares in computing net loss per share attributable to Class A and Class B common stockholders, basic (in shares)	39,470	23,433	12,735
Weighted-average shares in computing net loss per share attributable to Class A and Class B common stockholders, diluted (in shares)	39,470	23,433	12,735
Basic loss per common share (in usd per share)	$ (1.51)	$ (2.57)	$ (1.24)
Diluted loss per common share (in usd per share)	$ (1.51)	$ (2.57)	$ (1.24)

- Definition

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 65
-Paragraph 1
-Subparagraph (e)(4)
-URI https://asc.fasb.org/extlink&oid=126732423&loc=SL123482106-238011

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 3
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22583-107794

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 11
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22694-107794

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 10
-URI https://asc.fasb.org/extlink&oid=126958026&loc=d3e1448-109256

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 4
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22595-107794

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
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-Paragraph 11
-Subparagraph (a)
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 7
-URI https://asc.fasb.org/extlink&oid=126958026&loc=d3e1337-109256

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 65
-Paragraph 1
-Subparagraph (f)
-URI https://asc.fasb.org/extlink&oid=126732423&loc=SL123482106-238011

Reference 9: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 55
-Paragraph 52
-URI https://asc.fasb.org/extlink&oid=128363288&loc=d3e4984-109258

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(23))
-URI https://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 55
-Paragraph 15
-URI https://asc.fasb.org/extlink&oid=128363288&loc=d3e3842-109258

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
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LOSS PER SHARE - Narrative (Details) shares in Thousands	12 Months Ended
LOSS PER SHARE - Narrative (Details) shares in Thousands	Dec. 31, 2022 votePerShare shares
Performance Based RSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Founder awards where performance not met \| shares	1,620
Common Class A
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Voting rights, per share	1
Common Class B
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Voting rights, per share	20

LOSS PER SHARE - Schedule of Antidilutive Securities (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from the computation of earnings per share (in shares)	6,626	7,165	27,473
Founder awards where performance has been met
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from the computation of earnings per share (in shares)	180	180	0
Stock options outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from the computation of earnings per share (in shares)	4,410	6,255	8,365
RSUs outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from the computation of earnings per share (in shares)	2,036	730	34
Convertible preferred stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from the computation of earnings per share (in shares)	0	0	19,074