PubMatic (PUBM) 10-K 28 Feb 22 2021 FY Annual report Financial data

Cover

Cover - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Jan. 31, 2022	Jun. 30, 2021
Document Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2021
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-39748
Entity Registrant Name	PubMatic, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	20-5863224
Entity Address, Address Line One	3 Lagoon Drive
Entity Address, Address Line Two	Suite 180
Entity Address, City or Town	Redwood City
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94065
Title of 12(b) Security	Class A common stock, $0.0001 par value per share
Trading Symbol	PUBM
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	true
Entity Shell Company	false
Entity Public Float			$ 975.9
Documents Incorporated by Reference	Portions of the registrant’s proxy statement for its 2022 annual meeting of stockholders are incorporated herein by reference in Part III of this Annual Report on Form 10-K to the extent stated herein. Such proxy statement will be filed with the Securities and Exchange Commission within 120 days of the registrant’s fiscal year ended December 31, 2021.
Amendment Flag	false
Entity Central Index Key	0001422930
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Common Class A
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		40,775,004
Common Class B
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		11,098,925

Audit Information

Audit Information	12 Months Ended
	Dec. 31, 2021
Auditor Information [Abstract]
Auditor Name	DELOITTE & TOUCHE LLP
Auditor Firm ID	34
Auditor Location	San Jose, California

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current Assets
Cash and cash equivalents	$ 82,505	$ 81,188
Marketable securities	77,121	19,793
Accounts receivable - net	286,916	219,511
Prepaid expenses and other current assets	14,207	6,622
Total Current Assets	460,749	327,114
Property, equipment and software - net	50,140	30,044
Operating lease right-of-use assets	21,613	0
Goodwill	6,250	6,250
Deferred income tax asset	515	762
Other assets, non-current	10,948	7,076
TOTAL ASSETS	550,215	371,246
Current Liabilities
Accounts payable	244,321	176,731
Accrued expenses and other current liabilities	18,780	14,844
Operating lease liabilities, current	3,864	0
Total Current Liabilities	266,965	191,575
Operating lease liabilities, non-current	17,842	0
Deferred tax liability	6,067	1,561
Other liabilities, non-current	2,161	2,683
TOTAL LIABILITIES	293,035	195,819
Commitments and contingencies (Note 6)
Stockholders' Equity
Preferred stock, $0.0001 par value per share, 10,000,000 shares authorized as of December 31, 2021 and 2020; No shares issued and outstanding as of December 31, 2021 and 2020	0	0
Common stock, par value $0.0001 per share; 1,000,000,000 Class A shares authorized as of December 31, 2021 and 2020; 40,695,140 and 6,801,368 shares issued and outstanding as of December 31, 2021 and 2020, respectively; 1,000,000,000 Class B shares authorized as of December 31, 2021 and 2020; 11,159,609 and 42,186,774 shares issued and outstanding as of December 31, 2021 and 2020, respectively.	6	6
Treasury stock, at cost - 3,140,437 and 3,139,295 shares as of December 31, 2021 and 2020, respectively.	(11,486)	(11,434)
Additional paid-in capital	169,401	144,163
Accumulated other comprehensive income	(36)	1
Retained earnings	99,295	42,691
Total Stockholders' Equity	257,180	175,427
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 550,215	$ 371,246

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2021	Dec. 31, 2020
Preferred stock par value (in usd per share)	$ 0.0001	$ 0.0001
Preferred stock shares authorized	10,000,000	10,000,000
Preferred stock shares issued	0	0
Preferred stock shares outstanding	0	0
Treasury stock shares	3,140,437	3,139,295
Common Class A
Common stock par value (in usd per share)	$ 0.0001	$ 0.0001
Common stock shares authorized	1,000,000,000	1,000,000,000
Common stock shares issued	40,695,140	6,801,368
Common stock shares outstanding	40,695,140	6,801,368
Common Class B
Common stock par value (in usd per share)	$ 0.0001	$ 0.0001
Common stock shares authorized	1,000,000,000	1,000,000,000
Common stock shares issued	11,159,609	42,186,774
Common stock shares outstanding	11,159,609	42,186,774

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Statement [Abstract]
Revenue	$ 226,908	$ 148,748	$ 113,871
Cost of revenue	58,313	41,186	36,104
Gross profit	168,595	107,562	77,767
Operating expenses:
Technology and development	15,885	12,250	12,453
Sales and marketing	58,160	43,297	36,498
General and administration	35,761	20,260	20,307
Total operating expenses	109,806	75,807	69,258
Operating income	58,789	31,755	8,509
Interest income	300	537	1,290
Unrealized gain on equity investment	5,433	0	0
Other income (expense), net	281	(712)	(577)
Total other income (expense), net	6,014	(175)	713
Income before provision for income taxes	64,803	31,580	9,222
Provision for income taxes	8,199	4,967	2,579
Net income	$ 56,604	$ 26,613	$ 6,643
Net income per share attributable to common stockholders:
Basic (in usd per share)	$ 1.13	$ 0.51	$ 0.04
Diluted (in usd per share)	$ 1	$ 0.46	$ 0.04
Weighted-average shares used to compute net income per share attributable to common stockholders:
Basic (in shares)	50,184,455	12,642,293	10,036,983
Diluted (in shares)	56,628,574	17,125,882	12,169,884

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Statement of Other Comprehensive Income [Abstract]
Net income	$ 56,604	$ 26,613	$ 6,643
Other comprehensive income (loss):
Unrealized gain (loss) on marketable securities, net of tax	(37)	(5)	6
Comprehensive income	$ 56,567	$ 26,608	$ 6,649

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY - USD ($) $ in Thousands	Total	Common Stock	Treasury Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Retained Earnings	Convertible Preferred Stock	Redeemable Common Stock
Beginning balance (in shares) at Dec. 31, 2018							33,398,753	5,901,863
Beginning balance at Dec. 31, 2018							$ 60,820	$ 19,025
Increase (Decrease) in Temporary Equity [Roll Forward]
Cashless exercise of Series D convertible preferred stock warrants (in shares)							45,216
Cashless exercise of Series D convertible preferred stock warrants	$ 396						$ 396
Ending balance (in shares) at Dec. 31, 2019							33,443,969	5,901,863
Ending balance at Dec. 31, 2019							$ 61,216	$ 19,025
Beginning balance (in shares) at Dec. 31, 2018		5,726,954
Beginning balance at Dec. 31, 2018	4,625	$ 1	$ (11,426)	$ 6,615	$ 0	$ 9,435
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	2,022			2,022
Exercise of stock options (in shares)		20,983
Exercise of stock options	4			4
Repurchase of treasury stock, at cost (in shares)		(1,721)
Repurchase of treasury stock, at cost	(5)		(5)
Other comprehensive income (loss)	6				6
Net income	6,643					6,643
Ending balance (in shares) at Dec. 31, 2019		5,746,216
Ending balance at Dec. 31, 2019	13,295	$ 1	(11,431)	8,641	6	16,078
Increase (Decrease) in Temporary Equity [Roll Forward]
Cashless exercise of Series D convertible preferred stock warrants	0
Conversion of convertible preferred stock to common stock upon initial offering (in shares)							(33,443,969)
Conversion of convertible preferred stock to common stock upon initial offering							$ (61,216)
Ending balance (in shares) at Dec. 31, 2020							0	0
Ending balance at Dec. 31, 2020							$ 0	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	3,603			3,603
Exercise of stock options (in shares)		1,241,970
Exercise of stock options	2,409			2,409
Repurchase of treasury stock, at cost (in shares)		(876)
Repurchase of treasury stock, at cost	(3)		(3)
Repayment of shareholders notes receivable	4,268			4,268
Reclassification of common stock (in shares)		5,901,863						5,901,863
Reclassification of common stock	19,025	$ 1		19,024				$ (19,025)
Conversion of convertible preferred stock to common stock upon initial offering (in shares)		33,443,969
Conversion of convertible preferred stock to common stock upon initial offering	61,216	$ 3		61,213
Issuance of common stock upon initial public offering, net of underwriting discounts and commissions and other offering costs (in shares)		2,655,000
Sale of stock, consideration received on transaction	45,006	$ 1		45,005
Other comprehensive income (loss)	(5)				(5)
Net income	26,613					26,613
Ending balance (in shares) at Dec. 31, 2020		48,988,142
Ending balance at Dec. 31, 2020	175,427	$ 6	(11,434)	144,163	1	42,691
Increase (Decrease) in Temporary Equity [Roll Forward]
Cashless exercise of Series D convertible preferred stock warrants	0
Ending balance (in shares) at Dec. 31, 2021							0	0
Ending balance at Dec. 31, 2021							$ 0	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	$ 15,011			15,011
Exercise of stock options (in shares)	2,511,505	2,511,505
Exercise of stock options	$ 5,423			5,423
Repurchase of treasury stock, at cost (in shares)		(1,142)
Repurchase of treasury stock, at cost	(52)		(52)
Issuance of common stock related to employee stock purchase plan (in shares)		276,406
Issuance of common stock related to employee stock purchase plan	4,804			4,804
Issuance of common stock related to RSU vesting (in shares)		79,838
Other comprehensive income (loss)	(37)				(37)
Net income	56,604					56,604
Ending balance (in shares) at Dec. 31, 2021		51,854,749
Ending balance at Dec. 31, 2021	$ 257,180	$ 6	$ (11,486)	$ 169,401	$ (36)	$ 99,295

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Statement of Cash Flows [Abstract]
Net income	$ 56,604	$ 26,613	$ 6,643
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	23,073	15,743	12,671
Impairment of internally developed software	0	0	702
Unrealized gain on equity investment	(5,433)	0	0
Stock-based compensation	14,107	3,563	2,002
Provision for doubtful accounts	0	319	3,557
Change in fair value of preferred stock warrant liability	0	0	120
Deferred income taxes	4,753	2,933	193
Accretion of discount on marketable securities	(45)	(145)	(341)
Non-cash lease expense	2,042	0	0
Other	45	189	19
Changes in operating assets and liabilities:
Accounts receivable	(67,405)	(102,175)	(11,919)
Prepaid expenses and other assets	(7,681)	(2,801)	618
Accounts payable	68,301	77,357	18,465
Accrued expenses	3,530	3,452	2,011
Operating lease liabilities	(2,283)	0	0
Other liabilities, non-current	(927)	(718)	384
Net cash provided by operating activities	88,681	24,330	35,125
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of and deposits on property and equipment	(30,432)	(24,177)	(9,553)
Capitalized software development costs	(8,929)	(7,226)	(5,442)
Purchases of marketable securities	(90,562)	(36,704)	(37,545)
Proceeds from sales of marketable securities	0	2,295	696
Proceeds from maturities of marketable securities	33,200	35,950	30,255
Purchase of equity securities	0	(15)	(500)
Net cash used in investing activities	(96,723)	(29,877)	(22,089)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from initial public offering, net of underwriting discounts and commissions and other offering costs	(806)	45,811	0
Proceeds from repayments of stockholders’ notes receivable	0	4,268	0
Proceeds from issuance of common stock for employee stock purchase plan	4,804	0	0
Proceeds from exercise of stock options	5,423	2,409	4
Principal payments on finance lease obligations	(10)	0	0
Payments to acquire treasury stock	(52)	(3)	(5)
Net cash provided by (used in) financing activities	9,359	52,485	(1)
NET INCREASE IN CASH AND CASH EQUIVALENTS	1,317	46,938	13,035
CASH AND CASH EQUIVALENTS - Beginning of Year	81,188	34,250	21,215
CASH AND CASH EQUIVALENTS - End of Year	82,505	81,188	34,250
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Income taxes paid	6,786	2,691	3,016
SUPPLEMENTAL DISCLOSURES OF NON-CASH INVESTING AND FINANCING INFORMATION:
Stock-based compensation capitalized as internal use software costs	903	40	20
Property and equipment included in accounts payable and accrued expenses	49	111	770
Capitalized software costs included in accounts payable and accrued expenses	1,794	1,336	1,214
Non-cash exercise of convertible preferred stock warrant	0	0	396
Deferred offering costs incurred during the period included in accounts payable and accrued expenses	$ 0	$ 806	$ 0

Organization and Description of

Organization and Description of Business	12 Months Ended
	Dec. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Description of Business	Organization and Description of BusinessPubMatic, Inc. and subsidiaries (“Company” or “PubMatic”) was founded in 2006.

Basis of Presentation and Summa

Basis of Presentation and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Basis of Presentation and Summary of Significant Accounting Policies	Basis of Presentation and Summary of Significant Accounting Policies Fiscal Year The Company’s fiscal year ends on December 31. References to fiscal year 2021, for example, refer to the fiscal year ended December 31, 2021. Basis of Presentation The accompanying consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (“GAAP”). The accompanying consolidated financial statements include the accounts of PubMatic, Inc. and its wholly-owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. Use of Estimates The preparation of the consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts of assets and liabilities reported, disclosures about contingent assets and liabilities, and reported amounts of revenue and expenses. Significant items subject to such estimates include: revenue recognition criteria, including the determination of revenue reporting as net versus gross in the Company’s revenue arrangements, internal use software development costs, stock-based compensation, and income taxes, including the valuation reserve on deferred tax assets. The Company evaluates its estimates and assumptions on an ongoing basis using historical experience and other factors and adjusts those estimates and assumptions when facts and circumstances dictate. Actual results could materially differ from those estimates and assumptions. Due to the inherent uncertainty involved in making assumptions and estimates, events and changes in circumstances arising after December 31, 2021, including those resulting from the impacts of the COVID-19 pandemic, may result in actual outcomes that differ from those contemplated by the Company’s assumptions and estimates. Concentration of Credit Risk Financial instruments that potentially subject the Company to concentration of credit risk consist principally of cash and cash equivalents, marketable securities, and accounts receivable. The Company maintains its cash and cash equivalents with financial institutions in amounts which exceed Federal Deposit Insurance Corporation limits. The Company’s investment policy limits investments to certain types of securities issued by the U.S. government and its agencies and institutions with investment-grade credit ratings and places restrictions on maturities and concentration by type and issuer. The primary objective of its investment activities is to preserve principal while maximizing income without significantly increasing risk. Cash and Cash Equivalents The Company considers all highly liquid investments with an original maturity at the date of purchase of three months or less to be cash equivalents. Marketable Securities The Company classifies marketable securities as available-for-sale at the time of purchase and reevaluates such classification at each balance sheet date. The Company may sell these securities at any time for use in current operations even if they have not yet reached maturity. As a result, the Company classifies its marketable securities, including those with maturities beyond twelve months, as current assets in the consolidated balance sheets. These marketable securities are carried at fair value and unrealized gains and losses are recorded in other comprehensive income, which is reflected as a component of stockholders’ equity. These marketable securities are assessed as to whether those with unrealized loss positions are other than temporarily impaired. The Company considers impairments to be other than temporary if they are related to deterioration in credit risk or if it is likely the securities will be sold before the recovery of their cost basis. Realized gains and losses from the sale of marketable securities and declines in value deemed to be other than temporary are determined based on the specific identification method. Realized gains and losses, and any expected credit losses, are reported in other income (expense), net in the consolidated statements of operations and comprehensive income. Fair Value of Financial Instruments Financial instruments consist of cash equivalents, marketable securities, accounts receivable, equity investment, accounts payable, and accrued liabilities. Cash equivalents, marketable securities and equity investment are remeasured at fair value at the end of every period. Accounts receivable, accounts payable and accrued liabilities are stated at their carrying value, which approximates fair value due to the short time to the expected receipt or payment. Accounts Receivable and Allowance for Credit Losses (formerly Allowance for Doubtful Accounts) Accounts receivable are recorded at the invoiced amount, are unsecured, and do not bear interest. The allowance for credit losses is based on the best estimate of the amount of probable credit losses in existing accounts receivable. The allowance for credit losses is determined based on historical collection experience and the review in each period of the status of the then outstanding accounts receivable, while taking into consideration current customer information, collection history, and other relevant data. The Company reviews the allowance for credit losses on a quarterly basis. Account balances are written off against the allowance when the Company believes it is probable the receivable will not be recovered. The following table presents the changes in the allowance for credit losses (in thousands): December 31, 2021 2020 2019 Allowance for credit losses, beginning balance $ 1,989 $ 2,051 $ 1,784 Provision — 319 3,557 Write-offs (224) (381) (3,290) Allowance for credit losses, ending balance $ 1,765 $ 1,989 $ 2,051 Property and Equipment Property and equipment, including leasehold improvements, are stated at cost, less accumulated depreciation and amortization. Depreciation is computed using the straight-line method over the estimated useful lives of the related assets, generally three years. Leasehold improvements are amortized on a straight-line basis over the shorter of the estimated useful lives of the assets or the remaining lease term. Internal Use Software Development Costs The Company capitalizes certain internal use software development costs associated with creating and enhancing internal use software related to its platform and technology infrastructure. These costs include personnel and related employee benefits expenses for employees who are directly associated with and who devote time to software projects, and external direct costs of materials and services consumed in developing or obtaining the software. Software development costs that do not meet the criteria for capitalization are expensed as incurred and recorded in technology and development expenses in the consolidated statements of operations and comprehensive income. Software development activities generally consist of three stages, (i) the planning stage, (ii) the application and infrastructure development stage, and (iii) the post implementation stage. Costs incurred in the planning and post implementation stages of software development, including costs associated with the post configuration training and repairs and maintenance of the developed technologies, are expensed as incurred. The Company capitalizes costs associated with software developed for internal use when both the preliminary project stage is completed and management has authorized further funding for the completion of the project. Costs incurred in the application and infrastructure development stages, including significant enhancements and upgrades, are capitalized. Capitalization ends once a project is substantially complete and the software and technologies are ready for their intended purpose. Internal use software development costs are amortized using a straight-line method over the estimated useful life of two Impairment of Long-Lived Assets The Company continually monitors events and changes in circumstances that could indicate that carrying amounts of its long-lived assets, including property and equipment and intangible assets may not be recoverable. When such events or changes in circumstances occur, the Company assesses the recoverability of long-lived assets by determining whether the carrying value of such assets will be recovered through their undiscounted expected future cash flows. If the future undiscounted cash flows are less than the carrying value of these assets, the Company recognizes an impairment loss based on the excess of the carrying value over the fair value of the assets. Goodwill Goodwill represents the excess of the aggregate fair value of the consideration transferred in a business combination over the fair value of the assets acquired, net of liabilities assumed. The Company tests for impairment of goodwill annually during the fourth quarter or more frequently if events or changes in circumstances indicate that the goodwill may be impaired. Events or changes in circumstances which could trigger an impairment review include a significant adverse change in legal factors or in the business climate, an adverse action or assessment by a regulator, unanticipated competition, a loss of key personnel, significant changes in the manner of the Company’s use of the acquired assets, or the strategy for the Company’s overall business, significant negative industry or economic trends, or significant underperformance relative to expected historical or projected future results of operations. The Company has not recorded any goodwill impairment to date. Equity Investment Prior to December 2021, the Company accounted for investment in non-marketable equity securities that it does not exercise significant influence using the measurement alternative in accordance with Accounting Standards Update 2016-01. Under the measurement alternative, the carrying value is measured at cost, less any impairment, plus or minus changes resulting from observable price changes in orderly transactions for identical or similar investments of the same issuer. Adjustments are determined primarily based on a market approach as of the transaction date. During December 2021, an observable transaction occurred for such investment driven by a merger with a company registered with the U.S. Securities and Exchange Commission (SEC) and determined to have an active market. Therefore, the investment has readily determinable and observable fair value as of December 31, 2021 with realized and unrealized gains and losses included in Other (income) expense, net. The Company classifies its equity investment as Other assets, non-current on the Consolidated Balance Sheets. Revenue Recognition The Company recognizes revenue through the following steps: • Identification of a contract with a customer; • Identification of the performance obligations in the contract; • Determination of the transaction price; • Allocation of the transaction price to the performance obligations in the contract; and • Recognition of revenue when or as the performance obligations are satisfied. The Company refers to its publishers, app developers, and channel partners collectively as its publishers. The Company generates revenue through the monetization of publisher ad impressions on its platform. The Company’s platform allows publishers to sell, in real time, ad impressions to buyers and provides automated inventory management and monetization tools to publishers across various device types and digital ad formats. The Company charges publishers a fee, which is typically a percentage of the value of the ad impressions monetized through the Company’s platform. The Company maintains agreements with each publisher and buyer in the form of written service agreements, which set out the terms of the relationship, including payment terms (typically ninety days or less) and access to its platform. The Company invoices buyers for publisher digital advertising inventory purchased through its platform. The Company recognizes revenue when a bid is won and a buyer purchases inventory on its platform. The Company estimates and records reductions to revenue for rebates related to supply path optimization agreements based on expected volumes during the incentive term. The determination as to whether revenue should be reported gross of amounts billed to buyers (gross basis) or net of payments to publishers (net basis) requires significant judgment, and is based on the Company’s assessment of whether it is acting as the principal or an agent in the transaction. The Company has determined that it does not act as the principal in the purchase and sale of digital advertising inventory because it does not control the advertising inventory and it does not set the price which is the result of an auction within the marketplace. Based on these and other factors, the Company reports revenue on a net basis. The Company generally invoices buyers at the end of each month for the full purchase price of ad impressions monetized in that month. Accounts receivable are recorded at the amount of gross billings for the amounts it is responsible to collect, and accounts payable are recorded at the net amount payable to publishers. Accordingly, both accounts receivable and accounts payable appear large in relation to revenue reported on a net basis. Cost of Revenue Cost of revenue consists primarily of data center co-location costs, depreciation expense related to hardware supporting the Company’s platform, amortization expense related to capitalized internal use software development costs, personnel costs, and allocated facilities costs. Personnel costs include salaries, bonuses, stock- based compensation, and employee benefit costs, and are primarily attributable to the Company’s network operations group which maintains the Company’s servers and the Company’s client operations group, which is responsible for integration of new publishers and buyers and providing customer support for existing customers. Technology and Development Costs Technology and development expenses consist primarily of personnel costs, including salaries, bonuses, stock-based compensation, and employee benefits costs, allocated facilities costs, and professional services. These expenses include costs incurred in the development, implementation and maintenance of internal use software, including platform and related infrastructure. Technology and development costs are expensed as incurred, except to the extent that such costs are associated with internal use software development that meets the criteria for capitalization. The Company amortizes internal use software development costs that relate to its revenue producing activities on its platform to cost of revenue. Advertising Costs Advertising costs are expensed as incurred and are included in sales and marketing expenses. The Company’s advertising costs recorded during the years ended December 31, 2021, 2020 and 2019 were $0.5 million, $0.5 million and $0.3 million, respectively. Stock-Based Compensation Stock-based compensation expense related to stock awards, including stock options, restricted stock units (“RSUs”), and the employee stock purchase plan (the “ESPP”), is measured based on the fair value of the awards granted and recognized as an expense on a straight-line basis over the requisite service period. The fair value of each option and ESPP award is estimated on the grant date using the Black-Scholes option pricing model. The Black-Scholes option pricing model requires the input of highly subjective assumptions, including the fair value of the underlying common stock, the expected term of the award, the expected volatility of the price of our common stock, risk-free interest rates, and the expected dividend yield of our common stock. The fair value of each RSA and RSU award is based on the fair value of the underlying common stock as of the grant date. The assumptions used to determine the fair value of the stock awards represent management’s best estimates. These estimates involve inherent uncertainties and the application of management’s judgment. We account for forfeitures as they occur instead of estimating the number of awards expected to be forfeited. For additional information regarding stock-based compensation and the assumptions used for determining the fair value of stock options and ESPP awards, refer to Note 10—Stockholders’ Equity and Equity Incentive Plans. Foreign Currency Translation The functional currency of the Company’s foreign subsidiaries is the U.S. dollar. Accordingly, all monetary assets and liabilities of these subsidiaries are remeasured at the current exchange rate at each balance sheet date, nonmonetary assets and liabilities are measured at historical rates, and revenue and expenses are remeasured at average exchange rates during the period. Transaction gains and losses are included in other income (expense), net in the accompanying consolidated statements of operations and comprehensive income. The Company’s net foreign currency (gain) losses recorded during the years ended December 31, 2021, 2020 and 2019 were $0.1 million, $0.6 million, and $0.4 million respectively. Comprehensive Income Comprehensive income is composed of two components: net income and other comprehensive gain (loss). The Company’s changes in unrealized gains and losses on available-for-sale marketable securities represent the components of other comprehensive gain (loss) that are excluded from the reported net income. Income Taxes The Company utilizes the asset and liability method under which deferred tax assets and liabilities arise from the temporary differences between the tax basis of an asset or liability and its reported amount in the consolidated financial statements, as well as from net operating loss and tax credit carryforwards. Deferred tax amounts are determined by using the tax rates expected to be in effect when the taxes will actually be paid or refunds received, as provided for under currently enacted tax law. A valuation allowance is established when necessary to reduce deferred tax assets to the amount expected to be realized. The Company recognizes the tax benefit from an uncertain tax position only if it is more likely than not that the tax position will be sustained on examination by the taxing authorities, based on the technical merits of the position. The tax benefits recognized in the consolidated financial statements from such positions are then measured based on the largest benefit that has a greater than 50% likelihood of being realized. The Company recognizes interest and penalties related to income tax matters as income tax expense. Segment Information Operating segments are components of an enterprise for which separate financial information is available and is evaluated regularly by the Company’s chief operating decision maker in deciding how to allocate resources and assessing performance. The Company’s chief operating decision maker is its Chief Executive Officer. The Chief Executive Officer reviews financial information presented on a consolidated basis, for purposes of allocating resources and evaluating financial performance. The Company has one business activity and there are no segment managers accountable for operations, operating results beyond revenue or gross profit, or plans for levels or components below the consolidated unit level. Accordingly, the Company has a single reporting segment. Concentration of Revenue and Accounts Receivable The Company defines its revenue concentration based on revenue recognized from individual publishers. For the years ended December 31, 2021, 2020 and 2019, one publisher represented 17%, 20% and 28% respectively, of the Company’s revenue. As of December 31, 2021, two buyers accounted for 29% and 19%, respectively, of accounts receivable. As of December 31, 2020, four buyers accounted for 33%, 14%, 13% and 11%, respectively, of accounts receivable. Net Income Per Share Attributable to Common Stockholders Basic and diluted net income per share attributable to Class A and Class B common stock is computed in conformity with the two-class method required for participating securities. The Company applies the two-class method to allocate earnings between common and other participating securities based on their participation rights. Prior to the conversion of preferred stock to common stock concurrent with the IPO in December 2020 and because the holders of the Company’s convertible preferred stock were entitled to participate in dividends, the Company allocated net income to common and preferred stock based on their respective rights to receive dividends, whether or not declared. Distributed and undistributed earnings allocated to participating securities are subtracted from net income in determining net income attributable to common stockholders. Basic net income per share is computed by dividing net income attributable to common stockholders by the weighted-average number of shares of our Class A and Class B common stock outstanding. The diluted net income per share attributable to common stockholders is computed by giving effect to all dilutive securities. Diluted net income per share attributable to common stockholders is computed by dividing the resulting net income attributable to common stockholders by the weighted-average number of fully diluted common shares outstanding. During the periods when there is a net loss attributable to common stockholders, potentially dilutive common stock equivalents have been excluded from the calculation of diluted net loss per share attributable to common stockholders as their effect is anti-dilutive. Recently Adopted Accounting Pronouncements In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842), to increase transparency and comparability among organizations related to their leasing arrangements. This comprehensive new standard amends and supersedes existing lease accounting guidance and is intended to increase transparency and comparability among organizations by recognizing right-of-use (ROU) lease assets and lease liabilities on the balance sheet and requiring disclosure of key information about leasing arrangements. Lease expense continues to be recognized in a manner similar to legacy GAAP. The Company adopted the new lease standard on January 1, 2021 using the optional transition method to the modified retrospective approach. Under this transition provision, results for reporting periods beginning on January 1, 2021 are presented under Topic 842, while prior period amounts continue to be reported and disclosed in accordance with the Company’s historical accounting treatment under ASC Topic 840, Leases . To reduce the burden of adoption and ongoing compliance with Topic 842, a number of practical expedients and policy elections are available under the new guidance. The Company elected the "package of practical expedients" permitted under the transition guidance, which among other things, did not require reassessment of whether contracts entered into prior to adoption are or contain leases, and allowed carryforward of the historical lease classification for existing leases. The Company has not elected to adopt the “hindsight” practical expedient, and therefore will measure the ROU asset and lease liability using the remaining portion of the lease term at adoption on January 1, 2021. The Company made an accounting policy election under Topic 842 not to recognize right-of-use (ROU) assets and lease liabilities for leases with a term of twelve months or less. For all other leases, the Company recognizes ROU assets and lease liabilities based on the present value of lease payments over the lease term at the commencement date of the lease (or January 1, 2021 for existing leases upon the adoption of Topic 842). The ROU assets also include any initial direct costs incurred and lease payments made at or before the commencement date and are reduced by any lease incentives. The Company’s leases may include a non-lease component representing additional services transferred to the Company, such as common area maintenance for real estate. The Company made an accounting policy election to account for each separate lease component and the non-lease components associated with that lease component as a single lease component. As such, minimum lease payments include fixed payments for non-lease components within a lease agreement but exclude variable lease payments not dependent on an index or rate, such as common area maintenance, operating expenses, utilities, or other costs that are subject to fluctuation from period to period. Non-lease components that are variable in nature are recorded as variable lease expense in the period incurred. The Company uses its incremental borrowing rate to determine the present value of lease payments, as the Company’s leases do not have a readily determinable implicit discount rate. The incremental borrowing rate is the rate of interest the Company would have to pay to borrow on a collateralized basis over a similar term and amount in a similar economic environment. Judgement is applied in assessing factors such as Company-specific credit risk, lease term, nature and quality of the underlying collateral, currency, and economic environment in determining the incremental borrowing rate to apply to each lease. Adoption of Topic 842 resulted in the recording of ROU assets and lease liabilities related to the Company’s operating leases of approximately $2.8 million and $3.1 million, respectively, on January 1, 2021. The adoption of the new lease standard did not materially impact our consolidated net income or consolidated cash flows and did not result in a cumulative-effect adjustment to the opening balance of retained earnings. In June 2016, FASB issued ASU No. 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (ASU 2016-13). This update changes the accounting for recognizing impairments of financial assets, such that credit losses for certain types of financial instruments will be estimated based on expected losses. The update also modifies the impairment models for available-for-sale debt securities and for purchased financial assets with credit deterioration since their origination. The Company adopted ASU 2016-13 as of January 1, 2021. The standard did not have any material impact on its consolidated financial statements. In January 2017, the FASB issued ASU No. 2017-04, Intangibles—Goodwill and Other: Simplifying the Test for Goodwill Impairment (ASU 2017-04). ASU 2017-04 eliminates Step 2 from the goodwill impairment test which measures a goodwill impairment loss by comparing the implied fair value of a reporting unit’s goodwill with the carrying amount of that goodwill. Under ASU 2017-04, an entity should perform its annual or interim goodwill impairment test by comparing the fair value of the reporting unit with its carrying amount, and should recognize an impairment loss for the amount by which the carrying amount exceeds the reporting unit’s fair value, with the loss not exceeding the total amount of goodwill allocated to that reporting unit. The Company adopted ASU 2017-04 as of January 1, 2021. The standard did not have any material impact on its consolidated financial statements. In December 2019 the FASB issued ASU 2019-12—Simplifying the Accounting for Income Taxes (ASU 2019-12). ASU 2019-12 simplifies the accounting for income taxes by removing certain exceptions to general principles in Topic 740 and clarifies and amends existing guidance for clarity and consistent application.The Company adopted ASU 2019-12 as of January 1, 2021. The standard did not have a material impact on the condensed consolidated financial statements and related disclosures.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Assets and liabilities recorded at fair value on a recurring basis in the consolidated balance sheets are categorized based upon the level of judgment associated with the inputs used to measure their fair values. Fair value represents the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. The authoritative guidance on fair value measurements establishes a three-tier fair value hierarchy for disclosure of fair value measurements as follows: • Level I – Inputs are unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date; • Level II – Inputs are observable, unadjusted quoted prices in active markets for similar assets or liabilities, unadjusted quoted prices for identical or similar assets or liabilities in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the related assets or liabilities; and • Level III – Unobservable inputs that are significant to the measurement of the fair value of the assets or liabilities that are supported by little or no market data. A financial instrument’s categorization within the valuation hierarchy is based upon the lowest level of input that is significant to the fair value measurement. The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires management to make judgments and consider factors specific to the asset or liability. The Company’s financial assets consist of Level I and II assets. The Company had no Level III assets or liabilities for the periods presented. The Company classifies its cash equivalents and marketable securities within Level I or Level II because they are valued using either quoted market prices or inputs other than quoted prices which are directly or indirectly observable in the market, including readily-available pricing sources for the identical underlying security which may not be actively traded. The Company’s fixed income available-for-sale securities consist of high quality, investment grade securities from diverse issuers. The valuation techniques used to measure the fair value of the Company’s marketable securities were derived from non-binding market consensus prices that are corroborated by observable market data and quoted market prices for similar instruments. The following table sets forth the fair value of the Company’s financial assets and liabilities measured on a recurring basis by level within the fair value hierarchy (in thousands): December 31, 2021 Level I Level II Level III Total Financial Assets Money market funds $ 65,311 $ — $ — $ 65,311 Certificates of deposit — 5,942 — 5,942 Cash equivalents 65,311 5,942 — 71,253 Commercial paper — 50,954 — 50,954 U.S. Treasury and government debt securities — 26,167 — 26,167 Marketable securities — 77,121 — 77,121 Equity investment 5,948 — — 5,948 Non-current assets 5,948 — — 5,948 Total Financial Assets $ 71,259 $ 83,063 $ — $ 154,322 December 31, 2020 Level I Level II Level III Total Financial Assets Money market funds (1) $ 12,462 $ — $ — $ 12,462 Commercial paper (1) — 7,199 — 7,199 Cash equivalents 12,462 7,199 — 19,661 U.S. Treasury and government debt securities — 8,999 — 8,999 Commercial paper — 10,794 — 10,794 Marketable securities — 19,793 — 19,793 Total Financial Assets $ 12,462 $ 26,992 $ — $ 39,454 _______________ (1) The amounts were previously combined and presented as cash equivalents. Prior periods have been reclassified to conform with current period presentation.

Balance Sheet Components

Balance Sheet Components	12 Months Ended
	Dec. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Balance Sheet Components	Balance Sheet Components Marketable Securities The following table summarizes the Company’s marketable securities by significant investment categories (in thousands): December 31, 2021 Amortized Cost Gross Unrealized Gains Gross Unrealized Loss Fair Value Commercial paper $ 50,954 $ — $ — $ 50,954 U.S. Treasury and government debt securities 26,203 — (36) 26,167 Total $ 77,157 $ — $ (36) $ 77,121 December 31, 2020 Amortized Cost Gross Unrealized Gains Gross Unrealized Loss Fair Value Commercial paper $ 10,794 $ — $ — $ 10,794 U.S. Treasury and government debt securities 8,998 1 — 8,999 Total $ 19,792 $ 1 $ — $ 19,793 The remaining contractual maturity of all marketable securities was within one year as of December 31, 2021 and 2020. Realized gains and losses were not material for the years ended December 31, 2021, 2020 and 2019. As of December 31, 2021 and 2020, there were no securities that were in an unrealized loss position for more than twelve months. Property, Equipment and Software, Net Property, equipment and software, net consists of the following (in thousands): December 31, 2021 2020 Internal-use software $ 30,581 $ 24,513 Network hardware, computer equipment and software 92,561 62,764 Leasehold improvements 2,426 1,249 Furniture and fixtures 1,448 621 Property, equipment and software, gross 127,016 89,147 Less: accumulated depreciation and amortization (76,876) (59,103) Total property, equipment and software, net $ 50,140 $ 30,044 Depreciation and amortization expense related to property, equipment, and software (excluding amortization of internal use software) was $15.7 million, $9.8 million, and $6.9 million for the years ended December 31, 2021, 2020 and 2019, respectively. The Company capitalized $10.3 million, $7.3 million, and $6.0 million in software development costs during the years ended December 31, 2021, 2020 and 2019, respectively. Amortization expense of internal use software was $7.4 million, $5.9 million, and $5.4 million for the years ended December 31, 2021, 2020 and 2019, respectively. These costs are included within cost of revenue in the consolidated statements of operations and comprehensive income. The Company did not recognize any impairment charges on its long-lived assets during the year ended December 31, 2021 and 2020. During the year ended December 31, 2019 the Company discontinued offering its Unified Ad Server product which is part of capitalized software development and recorded a $0.7 million impairment charge in cost of revenue in the Company’s consolidated statement of operations and comprehensive income. Accounts Payable Accounts payable consists of the following (in thousands): December 31, 2021 2020 Payable to publishers $ 235,440 $ 168,673 Trade payables 8,881 8,058 Total accounts payable $ 244,321 $ 176,731 Accrued Expenses Accrued expenses consist of the following (in thousands): December 31, 2021 2020 Accrued compensation $ 17,271 $ 13,352 Accrued and other current liabilities 1,509 1,492 Total accrued expenses $ 18,780 $ 14,844

Loan and Security Agreement

Loan and Security Agreement	12 Months Ended
	Dec. 31, 2021
Debt Disclosure [Abstract]
Loan and Security Agreement	Loan and Security Agreement In June 2021, the Company amended and restated its loan and security agreement (the "Loan Agreement") with Silicon Valley Bank ("SVB".) The Loan Agreement provides a senior secured revolving credit facility of up to $25.0 million or 80% of eligible accounts receivable less certain reserves, minus the aggregate principal amount of all outstanding advances. Interest accrues on advances under the revolving line of credit at a variable rate equal to the greater of prime rate or 3.25%. As of December 31, 2021, the applicable interest rate under the revolving line of credit was 3.25%. An unused revolver fee in the amount of 0.40% per annum of the average unused portion of the revolver line is charged and is payable quarterly in arrears in any quarter where the average closing outstanding balance is less than $5.0 million. The maturity date of the revolving line of credit is June 6, 2024. As of December 31, 2021 there were no outstanding advances under the revolving line of credit. The Company’s obligations under the line of credit and the letters of credit (described in Note 6) with SVB are secured by substantially all of its assets excluding its intellectual property. The Loan Agreement contains affirmative covenants including financial covenants that, among other things, require the Company to maintain an adjusted quick ratio of no less than 1.00 to 1.00. The adjusted quick ratio is defined as the ratio of unrestricted cash and cash equivalents at SVB, plus billed accounts receivable to total accounts payable plus all SVB loans outstanding and outstanding letters of credit. The Loan Agreement also restricts the Company from paying dividends to stockholders without prior consent from SVB. The Company was in compliance with the financial covenants as of December 31, 2021.

Leases

Leases	12 Months Ended
	Dec. 31, 2021
Leases [Abstract]
Leases	Leases The Company determines if an arrangement is or contains a lease at inception, which is the date on which the terms of the contract are agreed to, and the agreement creates enforceable rights and obligations. Under Topic 842, a contract is or contains a lease when (i) explicitly or implicitly identified assets have been deployed in the contract and (ii) the customer obtains substantially all of the economic benefits from the use of that underlying asset and directs how and for what purpose the asset is used during the term of the contract. The Company also considers whether its service arrangements include the right to control the use of an asset. The Company leases office facilities from unrelated parties under operating lease agreements that have initial terms ranging from 2 to 10 years. Included in an office lease the Company also leases furniture and fixtures under a finance lease with a seven year term finance lease with a purchase option at the end of the term. The allocation of lease payments was determined based on the relative standalone price of the separate office and furniture components. Some leases include one or more options to renew, generally at our sole discretion, with renewal terms that can extend the lease term up to 10 additional years. In addition, certain leases contain termination options, where the rights to terminate are held by either the Company, the lessor, or both parties. These options to extend or terminate a lease are not included in the lease terms as the Company is not reasonably certain that they will exercise that option. The Company’s leases generally do not contain any material restrictive covenants. Operating lease cost is recognized on a straight-line basis over the lease term. Finance lease cost is recognized as a combination of the amortization expense for the ROU assets and interest expense for the outstanding lease liabilities, and results in a front-loaded expense pattern over the lease term. The components of lease expense are as follows: 2021 Operating lease cost $ 2,104 Finance lease cost - amortization of right-of-use assets 14 Finance lease cost - interest on lease liabilities 2 Total lease cost $ 2,120 Rent expense was approximately $2.5 million, $2.5 million, and $2.6 million for the year ended December 31, 2021, 2020, and 2019, respectively. Rent expense was offset by sublease income of $0.4 million and $0.6 million for the years ended December 31, 2020 and 2019, respectively. No sublease income was recognized for the year ended December 31, 2021. Short-term and variable lease expenses are not material to the Company’s consolidated financial statements. Supplemental cash flow information related to leases is as follows: 2021 Cash paid for amounts included in measurement of lease liabilities: Operating cash outflows - payments on operating leases $ 2,283 Right-of-use assets obtained in exchange for new lease obligations: Operating leases $ 20,887 Finance leases 869 Supplemental balance sheet information related to leases is as follows: 2021 Operating leases Operating lease right-of-use assets $ 21,613 Operating lease liabilities, current $ 3,864 Operating lease liabilities, non-current 17,842 Total operating lease liabilities $ 21,706 Finance leases Furniture and fixtures $ 869 Accumulated depreciation (14) Furniture and fixtures, net $ 855 Accrued liabilities $ 119 Other liabilities, non-current 741 Total finance lease liabilities $ 860 Weighted-average remaining lease term: Operating leases 6 years Finance leases 6.3 years Weighted-average discount rate: Operating leases 2.20 % Finance leases 2.24 % As of December 31, 2021, the maturities of lease liabilities under operating and finance leases were as follows: Year ending December 31, Operating leases Finance leases Total 2022 $ 4,298 $ 136 $ 4,434 2023 3,470 140 3,610 2024 3,459 145 3,604 2025 3,563 149 3,712 2026 3,670 153 3,823 Thereafter 4,750 200 4,950 Total minimum lease payments $ 23,210 $ 923 $ 24,133 Less: imputed interest (1,504) (63) (1,567) Total present value of lease liabilities $ 21,706 $ 860 $ 22,566 A summary of the future minimum lease commitments, as determined under Topic 840, for all non-cancelable operating lease agreements were as follows as of December 31, 2020: 2021 $ 2,179 2022 1,031 2023 108 Total minimum lease commitments $ 3,318
Leases	Leases The Company determines if an arrangement is or contains a lease at inception, which is the date on which the terms of the contract are agreed to, and the agreement creates enforceable rights and obligations. Under Topic 842, a contract is or contains a lease when (i) explicitly or implicitly identified assets have been deployed in the contract and (ii) the customer obtains substantially all of the economic benefits from the use of that underlying asset and directs how and for what purpose the asset is used during the term of the contract. The Company also considers whether its service arrangements include the right to control the use of an asset. The Company leases office facilities from unrelated parties under operating lease agreements that have initial terms ranging from 2 to 10 years. Included in an office lease the Company also leases furniture and fixtures under a finance lease with a seven year term finance lease with a purchase option at the end of the term. The allocation of lease payments was determined based on the relative standalone price of the separate office and furniture components. Some leases include one or more options to renew, generally at our sole discretion, with renewal terms that can extend the lease term up to 10 additional years. In addition, certain leases contain termination options, where the rights to terminate are held by either the Company, the lessor, or both parties. These options to extend or terminate a lease are not included in the lease terms as the Company is not reasonably certain that they will exercise that option. The Company’s leases generally do not contain any material restrictive covenants. Operating lease cost is recognized on a straight-line basis over the lease term. Finance lease cost is recognized as a combination of the amortization expense for the ROU assets and interest expense for the outstanding lease liabilities, and results in a front-loaded expense pattern over the lease term. The components of lease expense are as follows: 2021 Operating lease cost $ 2,104 Finance lease cost - amortization of right-of-use assets 14 Finance lease cost - interest on lease liabilities 2 Total lease cost $ 2,120 Rent expense was approximately $2.5 million, $2.5 million, and $2.6 million for the year ended December 31, 2021, 2020, and 2019, respectively. Rent expense was offset by sublease income of $0.4 million and $0.6 million for the years ended December 31, 2020 and 2019, respectively. No sublease income was recognized for the year ended December 31, 2021. Short-term and variable lease expenses are not material to the Company’s consolidated financial statements. Supplemental cash flow information related to leases is as follows: 2021 Cash paid for amounts included in measurement of lease liabilities: Operating cash outflows - payments on operating leases $ 2,283 Right-of-use assets obtained in exchange for new lease obligations: Operating leases $ 20,887 Finance leases 869 Supplemental balance sheet information related to leases is as follows: 2021 Operating leases Operating lease right-of-use assets $ 21,613 Operating lease liabilities, current $ 3,864 Operating lease liabilities, non-current 17,842 Total operating lease liabilities $ 21,706 Finance leases Furniture and fixtures $ 869 Accumulated depreciation (14) Furniture and fixtures, net $ 855 Accrued liabilities $ 119 Other liabilities, non-current 741 Total finance lease liabilities $ 860 Weighted-average remaining lease term: Operating leases 6 years Finance leases 6.3 years Weighted-average discount rate: Operating leases 2.20 % Finance leases 2.24 % As of December 31, 2021, the maturities of lease liabilities under operating and finance leases were as follows: Year ending December 31, Operating leases Finance leases Total 2022 $ 4,298 $ 136 $ 4,434 2023 3,470 140 3,610 2024 3,459 145 3,604 2025 3,563 149 3,712 2026 3,670 153 3,823 Thereafter 4,750 200 4,950 Total minimum lease payments $ 23,210 $ 923 $ 24,133 Less: imputed interest (1,504) (63) (1,567) Total present value of lease liabilities $ 21,706 $ 860 $ 22,566 A summary of the future minimum lease commitments, as determined under Topic 840, for all non-cancelable operating lease agreements were as follows as of December 31, 2020: 2021 $ 2,179 2022 1,031 2023 108 Total minimum lease commitments $ 3,318

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Contractual Obligations In the normal course of business, we enter into contractual obligations with various parties, primarily relate to minimum contractual payments due to data center providers. As of December 31, 2021, our outstanding contractual obligations with a term of 12 months or longer consist of the following (in thousands): Years ending December 31, Contractual Obligations 2022 10,506 2023 14,598 2024 6,540 2025 137 Total future minimum commitments, net $ 31,781 Letters of Credit As of December 31, 2021, the Company had two irrevocable letters of credit outstanding related to noncancelable facilities leases in the amounts of $3.5 million and $0.7 million, with annual automatic renewal and final expiration dates in July 2028 and June 2022, respectively. As of December 31, 2020, the Company had an irrevocable letter of credit outstanding related to noncancelable facilities leases in the amounts of $0.7 million, with annual automatic renewal and final expiration date in June 2022. Legal Matters From time to time, the Company has become involved in claims and other legal matters arising in the normal course of business. The Company investigates these claims as they arise and accrues for contingencies when the Company believes that a loss is probable and that the Company can reasonably estimate the amount of any such loss. The Company has made an assessment of the probability of incurring any such losses and whether or not those losses are estimable and although claims are inherently unpredictable the Company concluded that these losses are not material to the Company’s business, financial position, results of operations, or cash flows. To the extent there is a reasonable possibility that a loss exceeding amounts already recognized may be incurred, and the amount of such additional loss would be material, the Company will either disclose the estimated additional loss or state that such an estimate cannot be made. Indemnification In the normal course of business, the Company enters into contracts and agreements that contain a variety of representations and warranties and provide for general indemnification. The Company’s exposure under these agreements is unknown because it involves future claims that may be made against the Company, but have not yet been made. To date, the Company has not paid any material claims or been required to defend any actions related to its indemnification obligations. However, the Company may record charges in the future as a result of these indemnification obligations. In addition, the Company has indemnification agreements with certain of its directors and executive officers that require it, among other things, to indemnify them against certain liabilities that may arise due to their status or service as directors or officers of the Company. The terms of such obligations may vary.

Convertible Preferred Stock

Convertible Preferred Stock	12 Months Ended
	Dec. 31, 2021
Equity [Abstract]
Convertible Preferred Stock	Convertible Preferred Stock Upon completion of the IPO on December 11, 2020, all shares of convertible preferred stock outstanding, totaling 33,443,969 shares, were automatically converted into an equivalent number of shares of Class B common stock on a one-to-one basis and their carrying value of $61.2 million was reclassified into stockholders’ equity. As of December 31, 2020, there were no shares of convertible preferred stock issued and outstanding. In connection with the IPO, our amended and restated certificate of incorporation became effective, which authorized the issuance of 10,000,000 shares of undesignated preferred stock with a par value of $0.0001 with rights and preferences, including voting rights, designated from time to time by our board of directors.

Stockholders_ Notes Receivable

Stockholders’ Notes Receivable and Redeemable Common Stock	12 Months Ended
	Dec. 31, 2021
Equity [Abstract]
Stockholders’ Notes Receivable, Redeemable Common Stock and Stock Option Plans	Stockholders’ Notes Receivable and Redeemable Common Stock In August 2018, the Company loaned its Chief Executive Officer and Chief Growth Officer a total of $4.0 million under secured nonrecourse promissory notes (the “Notes”). Per the terms of the Notes, they had interest at a rate of 2.42% per annum compounded annually and matured on August 30, 2021, with interest and principal due at maturity. The Notes were secured by pledges of 1.6 million shares of outstanding common stock of the Company owned by the two officers (the “Pledged Shares”). As the Company’s only recourse on the Notes and associated interest was the Pledged Shares, the Notes were accounted for as nonrecourse and recorded to stockholders’ equity. This was accounted for as though the Company repurchased the Pledged Shares and in exchange issued the Notes and granted 1.6 million fully vested stock options with an exercise price equal to the face value of Notes plus interest. Incremental compensation expense of $1.0 million was recorded as stock-based compensation expense within the consolidated statements of operations and comprehensive income and was calculated as the difference between the Repurchase Price (defined as the face value of the Notes and the fair value of the stock options) and the fair value of the Pledged Shares. In year ended December 31, 2020, all principal and interest due under the notes were prepaid. No principal or interest payments were paid during the year ended December 31, 2021. In connection with the Notes, the Company provided the officers with a right to sell to the Company outstanding shares of common stock upon settlement of the Notes (the “Put Option”). The officers could have only exercised the Put Option upon repayment of the Notes using the Pledged Shares or upon the prepayment of the Notes using proceeds from the officers’ sale or disposal of the Pledged Shares at a price less than the face value of the Notes. The Put Option allowed the officers to require the Company to repurchase any or all common stock held or beneficially owned to offset their tax liabilities resulting from the settlement of the Notes via one of the above methods. As the exercisability of the Put Option and therefore redemption of the common stock was outside the control of the Company then all common stock held or beneficially owned by the officers required temporary equity classification. The Company therefore classified $19.0 million of common stock outside of stockholders’ equity, which represented the fair value of the shares held or beneficially owned on the transaction date. The Company did not adjust the carrying value of the redeemable common stock during the year ended December 31, 2019 since a redemption event was not probable. The Put Option expired unexercised upon the repayment of the Notes and during the Company’s quarter ended September 30, 2020, the $19.0 million of redeemable common stock has been reclassified back to common stock. Common Stock In connection with the IPO in December 2020, the Company’s restated certificate of incorporation became effective, which authorized 1,000,000,000 shares of Class A common stock, 0.0001 par value per share, and 1,000,000,000 shares of Class B common stock, 0.0001 par value per share. The rights of the holders of Class A common stock and Class B common stock are identical, except with respect to voting and conversion rights. Holders of Class A common stock are entitled to one vote and holders of Class B common stock are entitled to ten votes and is convertible into one share of Class A common stock. Each share of Class B is convertible anytime at the option of the holder into one share of Class A common stock. Once converted or transferred and converted into Class A common stock, the Class B common stock will not be reissued. Equity Incentive Plans Prior to the IPO, the Company maintained two equity incentive plans: the 2006 Stock Option Plan (the “2006 Plan”) and the 2017 Equity Incentive Plan. In February 2017, the Company adopted the 2017 Equity Incentive Plan (the “2017 Plan”) and all shares remaining unissued under the 2006 Stock Option Plan were assumed by the 2017 Plan. Upon completion of the IPO, the Company adopted the 2020 Equity Incentive Plan (“2020 Plan”), which serves as the successor to the 2017 Plan. Under the 2020 Plan, the Company may grant stock options, restricted stock awards, stock appreciation rights, restricted stock units (“RSUs”), deferred stock units (“DSUs”) performance awards, and stock bonus awards. As of December 31, 2021, the Company has reserved 6,386,698 shares of Class A common stock for the issuance of awards under the 2020 Plan. These available shares will increase automatically on January 1 for each of the first ten calendar years during the term of the 2020 Plan by the number of shares equal to the lesser of five percent (5%) of the aggregate number of outstanding shares of all classes of the Company’s common stock outstanding as of the immediately preceding December 31, or a number as may be determined by the Company’s board of directors or compensation committee. To the extent outstanding awards under the 2017 Plan and the 2006 Plan are forfeited, lapse unexercised, or would otherwise have been returned to the share reserve under the Prior Plans, the shares of Class B common stock subject to such awards instead will be available for future issuance as Class A common stock under the 2020 Plan. No new awards were issued under the 2006 Plan or 2017 Plan after the effective date of the 2020 Plan. Stock Options Stock options granted under the Company’s stock incentive plans generally vest over four years, subject to the holder’s continued service through the vesting date and expire no later than 10 years from the date of grant. The following summarizes stock option activity: Options Outstanding Number of Shares Underlying Outstanding Options Weighted-Average Exercise Price Weighted Average Remaining Contractual Term (Years) Aggregate Intrinsic Value (in thousands) Outstanding — December 31, 2020 8,459,969 $ 2.53 6.83 $ 215,144 Options granted 660,466 $ 36.74 Options exercised (2,511,505) $ 2.16 Options canceled (66,419) $ 6.38 Options expired (160) $ 0.26 Outstanding — December 31, 2021 6,542,351 $ 6.08 6.95 $ 184,727 Vested and exercisable — December 31, 2021 4,341,907 $ 3.56 6.17 $ 132,770 The aggregate intrinsic value represents the difference between the exercise price of the options and the fair market value of our common stock on the date of exercise. The intrinsic value of options exercised was $80.7 million, $15.7 million and $0.1 million for the years ended December 31, 2021, 2020 and 2019, respectively. The weighted-average grant date fair value of options granted was $20.30, $4.96 and $1.65 for the years ended December 31, 2021, 2020 and 2019, respectively. As of December 31, 2021, unrecognized stock-based compensation of $17.0 million related to unvested stock options will be recognized on a straight-line basis over a weighted average period of 2.69 years. The Black-Scholes assumptions used to value the employee options at the grant dates are as follows: Year Ended December 31, 2021 2020 2019 Fair market value of common stock $39.75-$54.07 $3.20-$17.00 $3.01-$3.18 Expected term (in years) 5.8-6.7 5.7-6.4 5.2-6.6 Risk-free interest rate 0.6%-1.0% 0.3%-1.5% 1.4%-2.6% Expected volatility 51%-54% 50%-55% 52%-54% Dividend rate —% —% —% Each of these inputs is subjective and generally requires significant judgment to determine. These assumptions and estimates were determined as follows: Fair Value of Common Stock - Prior to the Company’s IPO, the fair value was determined by the board of directors, with input from management and valuation reports prepared by third-party valuation specialists. After the Company’s IPO, the fair value of each share of underlying common stock was based on the closing price of our Class A common stock as reported on the date of the grant. Expected Term - The expected term represents the period that the Company’s stock-based awards are expected to be outstanding. For option grants that are considered to be “plain vanilla,” the Company determines the expected term using the simplified method. The simplified method deems the term to be the average of the time-to-vesting and the contractual life of the options. For other option grants, the Company estimates expected term using historical data on employee exercises and post-vesting employment termination behavior taking into account the contractual life of the award. Risk-Free Interest Rate - The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant for zero-coupon U.S. Treasury notes with maturities approximately equal to the option’s expected term. Expected Volatility - Since the Company has a short trading history of its common stock, the expected volatility is derived from the average historical stock volatilities of several unrelated public companies within the Company’s industry that the Company considers to be comparable to its business over a period equivalent to the expected term of the stock option grants. Dividend Rate - The expected dividend is assumed to be zero as the Company has never paid dividends and has no current plans to do so. Restricted Stock Units Restricted stock awards generally vest over four years, subject to the holder’s continued service through the vesting date. A summary of RSU activity under the Company’s equity incentive plan and related information is as follows: RSUs Number of Shares Weighted-Average Grant Date Fair Value per Share Aggregate Intrinsic Value (in thousands) Unvested — December 31, 2020 — $ — $ — Granted 582,259 35.24 — Vested (79,838) 35.91 — Canceled/Forfeited (19,119) 32.69 — Unvested — December 31, 2021 483,302 $ 35.23 $ 17,025 As of December 31, 2021, unrecognized stock-based compensation of $15.7 million related to unvested RSUs will be recognized on a straight-line basis over a weighted average period of 3.34 years. 2020 Employee Stock Purchase Plan In November 2020, the Company’s board of directors adopted, and its stockholders approved, the 2020 Employee Stock Purchase Plan (“ESPP”), which became effective in connection with the IPO. A total of 500,000 shares of the Company’s Class A common stock were initially reserved for issuance under the ESPP. The aggregate number of shares reserved for issuance under the ESPP will increase automatically on January 1st of each of the first ten calendar years during the term of the ESPP by the number of shares equal to the lesser of (a) 1% of the total outstanding shares of all classes of the Company’s common stock as of the immediately preceding December 31 and (b) such number of shares of common stock as determined by the Company’s board of directors. The aggregate number of shares issued over the term of the ESPP may not exceed 7,500,000 shares of Class A common stock. As of December 31, 2021, the Company has reserved 713,475 shares of its common stock for issuance under the ESPP. Under the ESPP, Class A common stock will be purchased for the accounts of employees participating in the ESPP on each purchase date at a price per share equal to 85% of the lesser of: (a) the fair market value on the offering date or (b) the fair market value on the purchase date. The ESPP provides for, at maximum, 27 month offering periods and each offering period may consist of one or more six-month purchase periods, beginning December 9, 2020 through May 31, 2022 with the purchase date on the last day of each purchase period. As of December 31, 2021, $0.3 million has been withheld on behalf of employees for a future purchase under the ESPP due to the timing of payroll deductions and is included in accrued and other current liabilities. For the twelve months ended December 31, 2021, 276,406 shares of our Class A common stock have been purchased under the ESPP. As of December 31, 2021, unrecognized stock-based compensation expense related to the ESPP was $1.4 million, which is expected to be recognized over a weighted-average period of 0.41 years. We estimated the fair value of ESPP purchase rights on the date of the grant using a Black-Scholes option-pricing model with the following assumptions: Year Ended December 31, 2021 Expected term (in years) 0.4-1.4 Risk-free interest rate 0.1% Expected volatility 60%-76% Dividend rate —% Expected Term - The expected term of the ESPP represents the period of time that purchase rights are expected to be outstanding. Risk-Free Interest Rate - The risk-free interest rate for the expected term of the awards was based on the U.S. Treasury yield curve in effect at the time of the grant. Expected Volatility - Since the Company has a short trading history of its common stock, the expected volatility was estimated by taking the average historic price volatility of several unrelated public companies within the Company’s industry that the Company considers to be comparable to its business over a period equivalent to the expected term of the awards. Dividend rate - The Company has never declared or paid any cash dividends and does not presently plan to pay cash dividends in the foreseeable future. As a result, an expected dividend yield of zero percent was used. Stock-Based Compensation The stock-based compensation expense by line item in the accompanying consolidated statements of operations is summarized as follows: December 31, 2021 2020 2019 Cost of revenue $ 825 $ 86 $ 26 Technology and development 2,232 599 402 Sales and marketing 5,176 1,101 684 General and administrative 5,874 1,777 890 Total stock-based compensation 14,107 3,563 2,002 Tax benefit from stock-based compensation (1,825) (493) (181) Total stock-based compensation, net of tax effect $ 12,282 $ 3,070 $ 1,821

Stockholders_ Equity and Equity

Stockholders’ Equity and Equity Incentive Plans	12 Months Ended
	Dec. 31, 2021
Equity [Abstract]
Stockholders’ Notes Receivable, Redeemable Common Stock and Stock Option Plans	Stockholders’ Notes Receivable and Redeemable Common Stock In August 2018, the Company loaned its Chief Executive Officer and Chief Growth Officer a total of $4.0 million under secured nonrecourse promissory notes (the “Notes”). Per the terms of the Notes, they had interest at a rate of 2.42% per annum compounded annually and matured on August 30, 2021, with interest and principal due at maturity. The Notes were secured by pledges of 1.6 million shares of outstanding common stock of the Company owned by the two officers (the “Pledged Shares”). As the Company’s only recourse on the Notes and associated interest was the Pledged Shares, the Notes were accounted for as nonrecourse and recorded to stockholders’ equity. This was accounted for as though the Company repurchased the Pledged Shares and in exchange issued the Notes and granted 1.6 million fully vested stock options with an exercise price equal to the face value of Notes plus interest. Incremental compensation expense of $1.0 million was recorded as stock-based compensation expense within the consolidated statements of operations and comprehensive income and was calculated as the difference between the Repurchase Price (defined as the face value of the Notes and the fair value of the stock options) and the fair value of the Pledged Shares. In year ended December 31, 2020, all principal and interest due under the notes were prepaid. No principal or interest payments were paid during the year ended December 31, 2021. In connection with the Notes, the Company provided the officers with a right to sell to the Company outstanding shares of common stock upon settlement of the Notes (the “Put Option”). The officers could have only exercised the Put Option upon repayment of the Notes using the Pledged Shares or upon the prepayment of the Notes using proceeds from the officers’ sale or disposal of the Pledged Shares at a price less than the face value of the Notes. The Put Option allowed the officers to require the Company to repurchase any or all common stock held or beneficially owned to offset their tax liabilities resulting from the settlement of the Notes via one of the above methods. As the exercisability of the Put Option and therefore redemption of the common stock was outside the control of the Company then all common stock held or beneficially owned by the officers required temporary equity classification. The Company therefore classified $19.0 million of common stock outside of stockholders’ equity, which represented the fair value of the shares held or beneficially owned on the transaction date. The Company did not adjust the carrying value of the redeemable common stock during the year ended December 31, 2019 since a redemption event was not probable. The Put Option expired unexercised upon the repayment of the Notes and during the Company’s quarter ended September 30, 2020, the $19.0 million of redeemable common stock has been reclassified back to common stock. Common Stock In connection with the IPO in December 2020, the Company’s restated certificate of incorporation became effective, which authorized 1,000,000,000 shares of Class A common stock, 0.0001 par value per share, and 1,000,000,000 shares of Class B common stock, 0.0001 par value per share. The rights of the holders of Class A common stock and Class B common stock are identical, except with respect to voting and conversion rights. Holders of Class A common stock are entitled to one vote and holders of Class B common stock are entitled to ten votes and is convertible into one share of Class A common stock. Each share of Class B is convertible anytime at the option of the holder into one share of Class A common stock. Once converted or transferred and converted into Class A common stock, the Class B common stock will not be reissued. Equity Incentive Plans Prior to the IPO, the Company maintained two equity incentive plans: the 2006 Stock Option Plan (the “2006 Plan”) and the 2017 Equity Incentive Plan. In February 2017, the Company adopted the 2017 Equity Incentive Plan (the “2017 Plan”) and all shares remaining unissued under the 2006 Stock Option Plan were assumed by the 2017 Plan. Upon completion of the IPO, the Company adopted the 2020 Equity Incentive Plan (“2020 Plan”), which serves as the successor to the 2017 Plan. Under the 2020 Plan, the Company may grant stock options, restricted stock awards, stock appreciation rights, restricted stock units (“RSUs”), deferred stock units (“DSUs”) performance awards, and stock bonus awards. As of December 31, 2021, the Company has reserved 6,386,698 shares of Class A common stock for the issuance of awards under the 2020 Plan. These available shares will increase automatically on January 1 for each of the first ten calendar years during the term of the 2020 Plan by the number of shares equal to the lesser of five percent (5%) of the aggregate number of outstanding shares of all classes of the Company’s common stock outstanding as of the immediately preceding December 31, or a number as may be determined by the Company’s board of directors or compensation committee. To the extent outstanding awards under the 2017 Plan and the 2006 Plan are forfeited, lapse unexercised, or would otherwise have been returned to the share reserve under the Prior Plans, the shares of Class B common stock subject to such awards instead will be available for future issuance as Class A common stock under the 2020 Plan. No new awards were issued under the 2006 Plan or 2017 Plan after the effective date of the 2020 Plan. Stock Options Stock options granted under the Company’s stock incentive plans generally vest over four years, subject to the holder’s continued service through the vesting date and expire no later than 10 years from the date of grant. The following summarizes stock option activity: Options Outstanding Number of Shares Underlying Outstanding Options Weighted-Average Exercise Price Weighted Average Remaining Contractual Term (Years) Aggregate Intrinsic Value (in thousands) Outstanding — December 31, 2020 8,459,969 $ 2.53 6.83 $ 215,144 Options granted 660,466 $ 36.74 Options exercised (2,511,505) $ 2.16 Options canceled (66,419) $ 6.38 Options expired (160) $ 0.26 Outstanding — December 31, 2021 6,542,351 $ 6.08 6.95 $ 184,727 Vested and exercisable — December 31, 2021 4,341,907 $ 3.56 6.17 $ 132,770 The aggregate intrinsic value represents the difference between the exercise price of the options and the fair market value of our common stock on the date of exercise. The intrinsic value of options exercised was $80.7 million, $15.7 million and $0.1 million for the years ended December 31, 2021, 2020 and 2019, respectively. The weighted-average grant date fair value of options granted was $20.30, $4.96 and $1.65 for the years ended December 31, 2021, 2020 and 2019, respectively. As of December 31, 2021, unrecognized stock-based compensation of $17.0 million related to unvested stock options will be recognized on a straight-line basis over a weighted average period of 2.69 years. The Black-Scholes assumptions used to value the employee options at the grant dates are as follows: Year Ended December 31, 2021 2020 2019 Fair market value of common stock $39.75-$54.07 $3.20-$17.00 $3.01-$3.18 Expected term (in years) 5.8-6.7 5.7-6.4 5.2-6.6 Risk-free interest rate 0.6%-1.0% 0.3%-1.5% 1.4%-2.6% Expected volatility 51%-54% 50%-55% 52%-54% Dividend rate —% —% —% Each of these inputs is subjective and generally requires significant judgment to determine. These assumptions and estimates were determined as follows: Fair Value of Common Stock - Prior to the Company’s IPO, the fair value was determined by the board of directors, with input from management and valuation reports prepared by third-party valuation specialists. After the Company’s IPO, the fair value of each share of underlying common stock was based on the closing price of our Class A common stock as reported on the date of the grant. Expected Term - The expected term represents the period that the Company’s stock-based awards are expected to be outstanding. For option grants that are considered to be “plain vanilla,” the Company determines the expected term using the simplified method. The simplified method deems the term to be the average of the time-to-vesting and the contractual life of the options. For other option grants, the Company estimates expected term using historical data on employee exercises and post-vesting employment termination behavior taking into account the contractual life of the award. Risk-Free Interest Rate - The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant for zero-coupon U.S. Treasury notes with maturities approximately equal to the option’s expected term. Expected Volatility - Since the Company has a short trading history of its common stock, the expected volatility is derived from the average historical stock volatilities of several unrelated public companies within the Company’s industry that the Company considers to be comparable to its business over a period equivalent to the expected term of the stock option grants. Dividend Rate - The expected dividend is assumed to be zero as the Company has never paid dividends and has no current plans to do so. Restricted Stock Units Restricted stock awards generally vest over four years, subject to the holder’s continued service through the vesting date. A summary of RSU activity under the Company’s equity incentive plan and related information is as follows: RSUs Number of Shares Weighted-Average Grant Date Fair Value per Share Aggregate Intrinsic Value (in thousands) Unvested — December 31, 2020 — $ — $ — Granted 582,259 35.24 — Vested (79,838) 35.91 — Canceled/Forfeited (19,119) 32.69 — Unvested — December 31, 2021 483,302 $ 35.23 $ 17,025 As of December 31, 2021, unrecognized stock-based compensation of $15.7 million related to unvested RSUs will be recognized on a straight-line basis over a weighted average period of 3.34 years. 2020 Employee Stock Purchase Plan In November 2020, the Company’s board of directors adopted, and its stockholders approved, the 2020 Employee Stock Purchase Plan (“ESPP”), which became effective in connection with the IPO. A total of 500,000 shares of the Company’s Class A common stock were initially reserved for issuance under the ESPP. The aggregate number of shares reserved for issuance under the ESPP will increase automatically on January 1st of each of the first ten calendar years during the term of the ESPP by the number of shares equal to the lesser of (a) 1% of the total outstanding shares of all classes of the Company’s common stock as of the immediately preceding December 31 and (b) such number of shares of common stock as determined by the Company’s board of directors. The aggregate number of shares issued over the term of the ESPP may not exceed 7,500,000 shares of Class A common stock. As of December 31, 2021, the Company has reserved 713,475 shares of its common stock for issuance under the ESPP. Under the ESPP, Class A common stock will be purchased for the accounts of employees participating in the ESPP on each purchase date at a price per share equal to 85% of the lesser of: (a) the fair market value on the offering date or (b) the fair market value on the purchase date. The ESPP provides for, at maximum, 27 month offering periods and each offering period may consist of one or more six-month purchase periods, beginning December 9, 2020 through May 31, 2022 with the purchase date on the last day of each purchase period. As of December 31, 2021, $0.3 million has been withheld on behalf of employees for a future purchase under the ESPP due to the timing of payroll deductions and is included in accrued and other current liabilities. For the twelve months ended December 31, 2021, 276,406 shares of our Class A common stock have been purchased under the ESPP. As of December 31, 2021, unrecognized stock-based compensation expense related to the ESPP was $1.4 million, which is expected to be recognized over a weighted-average period of 0.41 years. We estimated the fair value of ESPP purchase rights on the date of the grant using a Black-Scholes option-pricing model with the following assumptions: Year Ended December 31, 2021 Expected term (in years) 0.4-1.4 Risk-free interest rate 0.1% Expected volatility 60%-76% Dividend rate —% Expected Term - The expected term of the ESPP represents the period of time that purchase rights are expected to be outstanding. Risk-Free Interest Rate - The risk-free interest rate for the expected term of the awards was based on the U.S. Treasury yield curve in effect at the time of the grant. Expected Volatility - Since the Company has a short trading history of its common stock, the expected volatility was estimated by taking the average historic price volatility of several unrelated public companies within the Company’s industry that the Company considers to be comparable to its business over a period equivalent to the expected term of the awards. Dividend rate - The Company has never declared or paid any cash dividends and does not presently plan to pay cash dividends in the foreseeable future. As a result, an expected dividend yield of zero percent was used. Stock-Based Compensation The stock-based compensation expense by line item in the accompanying consolidated statements of operations is summarized as follows: December 31, 2021 2020 2019 Cost of revenue $ 825 $ 86 $ 26 Technology and development 2,232 599 402 Sales and marketing 5,176 1,101 684 General and administrative 5,874 1,777 890 Total stock-based compensation 14,107 3,563 2,002 Tax benefit from stock-based compensation (1,825) (493) (181) Total stock-based compensation, net of tax effect $ 12,282 $ 3,070 $ 1,821

Net Income Per Share Attributab

Net Income Per Share Attributable to Common Stockholders	12 Months Ended
	Dec. 31, 2021
Earnings Per Share [Abstract]
Net Income Per Share Attributable to Common Stockholders	Net Income Per Share Attributable to Common StockholdersThe Company has two classes of common stock, Class A and Class B. 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. As the liquidation and dividend rights are identical, the undistributed earnings are allocated on a proportionate basis and the resulting net loss per share attributed to common stockholders will, therefore, be the same for both Class A and Class B common stock on an individual or combined basis. The following table sets forth the computation of the Company’s basic and diluted net income per share (in thousands, except share and per share data): Year Ended December 31, 2021 2020 2019 (in thousands, except share and per share data) Numerator: Net income $ 56,604 $ 26,613 $ 6,643 Less: Undistributed earnings allocated to participating securities — (20,187) (6,204) Net income attributable to common stockholders – basic $ 56,604 $ 6,426 $ 439 Denominator: Weighted average common shares outstanding – basic 50,184,455 12,642,293 10,036,983 Net income per share attributable to common stockholders – basic: $ 1.13 $ 0.51 $ 0.04 Numerator: Net income attributable to common stockholders - diluted $ 56,604 $ 7,929 $ 508 Denominator: Weighted average shares outstanding – basic 50,184,455 12,642,293 10,036,983 Options to purchase common stock 6,353,779 4,483,589 2,119,796 Restricted stock 29,662 — — Employee stock purchase plan shares 60,678 — — Warrants to purchase common stock — — 13,105 Weighted average shares outstanding – diluted 56,628,574 17,125,882 12,169,884 Net income per share attributable to common stockholders – diluted $ 1.00 $ 0.46 $ 0.04 The following weighted-average outstanding shares of common stock equivalents were excluded from the computation of diluted net income per share attributable to common stockholders for the periods presented because including them would have been anti-dilutive: Year Ended December 31, 2021 2020 2019 Options to purchase common stock 671,244 846,481 3,359,458 Common stock issuable upon conversion of convertible preferred stock — — 33,410,274 Total excludable from net income per share attributable to common stockholders – diluted 671,244 846,481 36,769,732

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The following table presents domestic and foreign components of income (loss) before income taxes for the periods presented (in thousands): December 31, 2021 2020 2019 Domestic $ 61,822 $ 28,169 $ 6,995 International 2,981 3,411 2,227 Income before provision for income taxes $ 64,803 $ 31,580 $ 9,222 The income tax (benefit) provision is composed of the following (in thousands): December 31, 2021 2020 2019 Current provisions for income taxes: Federal $ 2,437 $ 360 $ 1,639 State 714 240 58 Foreign 295 1,434 689 Total current tax expense 3,446 2,034 2,386 Deferred tax expense: Federal $ 4,513 $ 1,845 $ 254 State 251 1,170 4 Foreign (11) (82) (65) Total deferred tax expense 4,753 2,933 193 Total provision for income taxes $ 8,199 $ 4,967 $ 2,579 The following table presents a reconciliation of the statutory federal rate and the Company’s effective tax rate for the periods presented: December 31, 2021 2020 2019 Statutory federal income tax rate 21.00 % 21.00 % 21.00 % State after-tax rate 1.49 4.47 0.67 Stock options (10.38) (6.79) 5.48 Research credit (1.37) (2.04) (2.85) Transfer pricing reserve (1.26) 1.32 (0.68) Foreign rate differential 0.73 0.61 2.37 Foreign derived intangible income (0.48) (3.26) (7.89) Section 162(m) limitation 2.49 — — Other 0.42 0.42 9.86 12.64 % 15.73 % 27.96 % Deferred income taxes reflect the net tax effects of temporary differences between carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. The following table presents the significant components of the Company’s deferred tax assets and liabilities for the periods presented (in thousands): December 31, 2021 2020 2019 Deferred tax assets: Net operating loss carryforwards $ 56 $ 124 $ 194 Accruals and allowances 1,104 614 784 Tax credits 1,396 1,631 1,064 Stock-based compensation 3,171 2,045 1,749 Intangibles assets 1,010 1,106 1,202 Lease obligation 5,226 — — Other 808 1,101 967 Valuation allowance (1,396) (1,372) — Total deferred tax assets 11,375 5,249 5,960 Deferred tax liabilities: Property, equipment, and software (8,316) (4,995) (3,003) Goodwill (749) (653) (562) Prepaid expense (1,365) (400) (256) Right-of-use asset (5,201) — — Unrealized gain on equity investment (1,296) — — Total deferred tax liabilities (16,927) (6,048) (3,821) Net deferred income tax asset (liabilities) $ (5,552) $ (799) $ 2,139 The Company had gross state net operating loss carryforwards of approximately $1.9 million as of December 31, 2021. These net operating losses will expire at various dates beginning in 2035 if not utilized and may be subject to annual limitations of usage, as promulgated by the Internal Revenue Service, due to ownership changes that may have occurred in the past. As of December 31, 2021, the Company had state research and development credit carryforwards of $2.9 million. The state credits can be carried forward indefinitely. Pursuant to Section 382 of the Internal Revenue Code of 1986, as amended (“Code”), the Company’s ability to utilize net operating loss carryforwards or other tax attributes, such as research tax credits, in any taxable year may be limited if the Company experiences an “ownership change.” A Section 382 “ownership change” generally occurs if one or more stockholders or groups of stockholders who own at least 5% of the Company’s stock increase their ownership by more than 50 percentage points over their lowest ownership percentage within a rolling three year period. Similar rules may apply under state tax laws. Net operating loss carryforwards and other tax attributes generated are currently not subject to limitation by Section 382, but subsequent changes in the Company’s stock ownership as well as other changes that may be outside of the Company’s control, could result in additional ownership changes under Section 382 of the Code. Deferred Tax Valuation Allowance A valuation allowance is provided for deferred tax assets where the recoverability of the assets is uncertain. The determination to provide a valuation allowance is dependent upon the assessment of whether it is more likely than not that sufficient future taxable income will be generated to utilize the deferred tax assets. Management has determined that there is sufficient positive evidence that a valuation allowance against deferred tax assets is not required as of December 31, 2021 and 2020, except for state research credit carryforwards, starting in 2020, for which realization is not deemed more likely than not given the Company expects to generate more credits in future than can be utilized against projected taxable income. The Company has not historically provided for U.S. deferred taxes on the cumulative earnings of non-U.S. affiliates that have been reinvested indefinitely. However, under the 2017 Tax Act the Company was deemed to have repatriated the cumulative earnings of its non-U.S. affiliates and the U.S. liability associated with those cumulative earnings has been reflected in the current federal tax provision. In addition, the Tax Act has enacted tax provisions that will subject all foreign earnings to U.S. taxation. The Company will continue to maintain its policy of indefinite reinvestment to the extent that the repatriation of foreign earnings are restricted by local laws, accounting rules, substantial incremental costs associated with repatriating the foreign earnings, or other business requirements. Uncertain Tax Positions The activity related to the unrecognized income tax benefits is as follows (in thousands): Year Ended December 31, 2021 2020 2019 Gross unrecognized income tax benefits — beginning balance $ 3,208 $ 2,369 $ 2,210 Increases related to tax positions taken during the current year 649 951 541 Decreases related to tax positions taken during prior years (1,493) (112) (382) Increases related to tax positions taken during the prior years — — — Gross unrecognized income tax benefits — ending balance $ 2,364 $ 3,208 $ 2,369 The Company recognizes interest and penalties, if any, related to uncertain tax positions in its income tax provision. As of December 31, 2021 and 2020, the Company had approximately $0.1 million and $0.3 million, respectively, of accrued interest related to uncertain tax positions. All of the $2.4 million of unrecognized income tax benefits would, if recognized, impact the effective tax rate in the period in which each of the benefits is recognized. The Company files U.S., state and foreign income tax returns with varying statutes of limitations. The federal, state, and foreign returns statute of limitations remains open for tax years from 2013 and thereafter. The Company is currently under audit by the IRS for the U.S. 2019 federal tax return. There are currently no income tax audits involving any U.S. states or foreign tax jurisdictions.

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2021
Segment Reporting [Abstract]
Segment Information	Segment Information The following table represents total revenue by geographic area based on the publisher’s billing address (in thousands): Year Ended December 31, 2021 2020 2019 United States $ 139,049 $ 96,886 $ 77,314 EMEA 62,531 34,156 23,642 APAC 20,910 15,087 10,988 Rest of the world 4,418 2,619 1,927 Total $ 226,908 $ 148,748 $ 113,871 The Company’s long-lived assets, net by geographic area are summarized as follows (in thousands): Year Ended December 31, 2021 2020 United States $ 42,059 $ 24,580 Rest of the world 8,081 5,464 Total $ 50,140 $ 30,044

401(k) Plan

401(k) Plan	12 Months Ended
	Dec. 31, 2021
Retirement Benefits [Abstract]
401(k) Plan	401(k) PlanThe Company has a 401(k) Savings Plan (the “401(k) Plan”) that qualifies as a deferred salary arrangement under Section 401(k) of the Internal Revenue Code. Under the 401(k) Plan, participating employees may elect to contribute up to 100% of their eligible compensation, subject to certain limitations. The 401(k) Plan provides for a discretionary employer matching contribution. The Company made no matching contribution to the 401(k) Plan for the year ended December 31, 2021 and December 31, 2020.

Basis of Presentation and Sum_2

Basis of Presentation and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (“GAAP”). The accompanying consolidated financial statements include the accounts of PubMatic, Inc. and its wholly-owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation.
Use of Estimates	Use of Estimates The preparation of the consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts of assets and liabilities reported, disclosures about contingent assets and liabilities, and reported amounts of revenue and expenses. Significant items subject to such estimates include: revenue recognition criteria, including the determination of revenue reporting as net versus gross in the Company’s revenue arrangements, internal use software development costs, stock-based compensation, and income taxes, including the valuation reserve on deferred tax assets. The Company evaluates its estimates and assumptions on an ongoing basis using historical experience and other factors and adjusts those estimates and assumptions when facts and circumstances dictate. Actual results could materially differ from those estimates and assumptions.
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments that potentially subject the Company to concentration of credit risk consist principally of cash and cash equivalents, marketable securities, and accounts receivable. The Company maintains its cash and cash equivalents with financial institutions in amounts which exceed Federal Deposit Insurance Corporation limits. The Company’s investment policy limits investments to certain types of securities issued by the U.S. government and its agencies and institutions with investment-grade credit ratings and places restrictions on
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments with an original maturity at the date of purchase of three months or less to be cash equivalents.
Marketable Securities	Marketable Securities The Company classifies marketable securities as available-for-sale at the time of purchase and reevaluates such classification at each balance sheet date. The Company may sell these securities at any time for use in current operations even if they have not yet reached maturity. As a result, the Company classifies its marketable securities, including those with maturities beyond twelve months, as current assets in the consolidated balance sheets. These marketable securities are carried at fair value and unrealized gains and losses are recorded in other comprehensive income, which is reflected as a component of stockholders’ equity. These marketable securities are assessed as to whether those with unrealized loss positions are other than temporarily impaired. The Company considers impairments to be other than temporary if they are related to deterioration in credit risk or if it is likely the securities will be sold before the recovery of their cost basis. Realized gains and losses from the sale of marketable securities and declines in value deemed to be other than temporary are determined based on the specific identification method. Realized gains and losses, and any expected credit losses, are reported in other income (expense), net in the consolidated statements of operations and comprehensive income.
Fair Value of Financial Instruments	Fair Value of Financial Instruments Financial instruments consist of cash equivalents, marketable securities, accounts receivable, equity investment, accounts payable, and accrued liabilities. Cash equivalents, marketable securities and equity investment are remeasured at fair value at the end of every period. Accounts receivable, accounts payable and accrued liabilities are stated at their carrying value, which approximates fair value due to the short time to the expected receipt or payment.
Accounts Receivable and Allowance for Credit Losses (formerly Allowance for Doubtful Accounts)	Accounts Receivable and Allowance for Credit Losses (formerly Allowance for Doubtful Accounts)Accounts receivable are recorded at the invoiced amount, are unsecured, and do not bear interest. The allowance for credit losses is based on the best estimate of the amount of probable credit losses in existing accounts receivable. The allowance for credit losses is determined based on historical collection experience and the review in each period of the status of the then outstanding accounts receivable, while taking into consideration current customer information, collection history, and other relevant data. The Company reviews the allowance for credit losses on a quarterly basis. Account balances are written off against the allowance when the Company believes it is probable the receivable will not be recovered.
Property and Equipment	Property and Equipment Property and equipment, including leasehold improvements, are stated at cost, less accumulated depreciation and amortization. Depreciation is computed using the straight-line method over the estimated useful
Internal Use Software Development Costs	Internal Use Software Development Costs The Company capitalizes certain internal use software development costs associated with creating and enhancing internal use software related to its platform and technology infrastructure. These costs include personnel and related employee benefits expenses for employees who are directly associated with and who devote time to software projects, and external direct costs of materials and services consumed in developing or obtaining the software. Software development costs that do not meet the criteria for capitalization are expensed as incurred and recorded in technology and development expenses in the consolidated statements of operations and comprehensive income. Software development activities generally consist of three stages, (i) the planning stage, (ii) the application and infrastructure development stage, and (iii) the post implementation stage. Costs incurred in the planning and post implementation stages of software development, including costs associated with the post configuration training and repairs and maintenance of the developed technologies, are expensed as incurred. The Company capitalizes costs associated with software developed for internal use when both the preliminary project stage is completed and management has authorized further funding for the completion of the project. Costs incurred in the application and infrastructure development stages, including significant enhancements and upgrades, are capitalized. Capitalization ends once a project is substantially complete and the software and technologies are ready for their intended purpose. Internal use software development costs are amortized using a straight-line method over the estimated useful life of two
Impairment of Long-Lived Assets	Impairment of Long-Lived AssetsThe Company continually monitors events and changes in circumstances that could indicate that carrying amounts of its long-lived assets, including property and equipment and intangible assets may not be recoverable. When such events or changes in circumstances occur, the Company assesses the recoverability of long-lived assets by determining whether the carrying value of such assets will be recovered through their undiscounted expected future cash flows. If the future undiscounted cash flows are less than the carrying value of these assets, the Company recognizes an impairment loss based on the excess of the carrying value over the fair value of the assets.
Goodwill	Goodwill Goodwill represents the excess of the aggregate fair value of the consideration transferred in a business combination over the fair value of the assets acquired, net of liabilities assumed. The Company tests for impairment of goodwill annually during the fourth quarter or more frequently if events or changes in circumstances indicate that the goodwill may be impaired. Events or changes in circumstances which could trigger an impairment review include a significant adverse change in legal factors or in the business climate, an adverse action or assessment by a regulator, unanticipated competition, a loss of key personnel, significant changes in the manner of the Company’s use of the acquired assets, or the strategy for the Company’s overall business, significant negative industry or economic trends, or significant underperformance relative to expected historical or projected future results of operations. The Company has not recorded any goodwill impairment to date.
Equity Investments	Equity Investment Prior to December 2021, the Company accounted for investment in non-marketable equity securities that it does not exercise significant influence using the measurement alternative in accordance with Accounting Standards Update 2016-01. Under the measurement alternative, the carrying value is measured at cost, less any impairment, plus or minus changes resulting from observable price changes in orderly transactions for identical or similar investments of the same issuer. Adjustments are determined primarily based on a market approach as of the
Revenue Recognition and Cost of Revenue	Revenue Recognition The Company recognizes revenue through the following steps: • Identification of a contract with a customer; • Identification of the performance obligations in the contract; • Determination of the transaction price; • Allocation of the transaction price to the performance obligations in the contract; and • Recognition of revenue when or as the performance obligations are satisfied. The Company refers to its publishers, app developers, and channel partners collectively as its publishers. The Company generates revenue through the monetization of publisher ad impressions on its platform. The Company’s platform allows publishers to sell, in real time, ad impressions to buyers and provides automated inventory management and monetization tools to publishers across various device types and digital ad formats. The Company charges publishers a fee, which is typically a percentage of the value of the ad impressions monetized through the Company’s platform. The Company maintains agreements with each publisher and buyer in the form of written service agreements, which set out the terms of the relationship, including payment terms (typically ninety days or less) and access to its platform. The Company invoices buyers for publisher digital advertising inventory purchased through its platform. The Company recognizes revenue when a bid is won and a buyer purchases inventory on its platform. The Company estimates and records reductions to revenue for rebates related to supply path optimization agreements based on expected volumes during the incentive term. The determination as to whether revenue should be reported gross of amounts billed to buyers (gross basis) or net of payments to publishers (net basis) requires significant judgment, and is based on the Company’s assessment of whether it is acting as the principal or an agent in the transaction. The Company has determined that it does not act as the principal in the purchase and sale of digital advertising inventory because it does not control the advertising inventory and it does not set the price which is the result of an auction within the marketplace. Based on these and other factors, the Company reports revenue on a net basis. The Company generally invoices buyers at the end of each month for the full purchase price of ad impressions monetized in that month. Accounts receivable are recorded at the amount of gross billings for the amounts it is responsible to collect, and accounts payable are recorded at the net amount payable to publishers. Accordingly, both accounts receivable and accounts payable appear large in relation to revenue reported on a net basis. Cost of Revenue Cost of revenue consists primarily of data center co-location costs, depreciation expense related to hardware supporting the Company’s platform, amortization expense related to capitalized internal use software development costs, personnel costs, and allocated facilities costs. Personnel costs include salaries, bonuses, stock-
Technology and Development Costs	Technology and Development CostsTechnology and development expenses consist primarily of personnel costs, including salaries, bonuses, stock-based compensation, and employee benefits costs, allocated facilities costs, and professional services. These expenses include costs incurred in the development, implementation and maintenance of internal use software, including platform and related infrastructure. Technology and development costs are expensed as incurred, except to the extent that such costs are associated with internal use software development that meets the criteria for capitalization. The Company amortizes internal use software development costs that relate to its revenue producing activities on its platform to cost of revenue.
Advertising Costs	Advertising CostsAdvertising costs are expensed as incurred and are included in sales and marketing expenses.
Stock-Based Compensation	Stock-Based Compensation Stock-based compensation expense related to stock awards, including stock options, restricted stock units (“RSUs”), and the employee stock purchase plan (the “ESPP”), is measured based on the fair value of the awards granted and recognized as an expense on a straight-line basis over the requisite service period. The fair value of each option and ESPP award is estimated on the grant date using the Black-Scholes option pricing model. The Black-Scholes option pricing model requires the input of highly subjective assumptions, including the fair value of the underlying common stock, the expected term of the award, the expected volatility of the price of our common stock, risk-free interest rates, and the expected dividend yield of our common stock. The fair value of each RSA and RSU award is based on the fair value of the underlying common stock as of the grant date. The assumptions used to determine the fair value of the stock awards represent management’s best estimates. These estimates involve inherent uncertainties and the application of management’s judgment. We account for forfeitures as they occur instead of estimating the number of awards expected to be forfeited. For additional information regarding stock-based compensation and the assumptions used for determining the fair value of stock options and ESPP awards, refer to Note 10—Stockholders’ Equity and Equity Incentive Plans.
Foreign Currency Translation	Foreign Currency TranslationThe functional currency of the Company’s foreign subsidiaries is the U.S. dollar. Accordingly, all monetary assets and liabilities of these subsidiaries are remeasured at the current exchange rate at each balance sheet date, nonmonetary assets and liabilities are measured at historical rates, and revenue and expenses are remeasured at average exchange rates during the period. Transaction gains and losses are included in other income (expense), net in the accompanying consolidated statements of operations and comprehensive income.
Comprehensive Income	Comprehensive Income Comprehensive income is composed of two components: net income and other comprehensive gain (loss). The Company’s changes in unrealized gains and losses on available-for-sale marketable securities represent the components of other comprehensive gain (loss) that are excluded from the reported net income.
Income Taxes	Income Taxes The Company utilizes the asset and liability method under which deferred tax assets and liabilities arise from the temporary differences between the tax basis of an asset or liability and its reported amount in the consolidated financial statements, as well as from net operating loss and tax credit carryforwards. Deferred tax amounts are determined by using the tax rates expected to be in effect when the taxes will actually be paid or refunds received, as provided for under currently enacted tax law. A valuation allowance is established when necessary to reduce deferred tax assets to the amount expected to be realized. The Company recognizes the tax benefit from an uncertain tax position only if it is more likely than not that the tax position will be sustained on examination by the taxing authorities, based on the technical merits of the position. The tax benefits recognized in the consolidated financial statements from such positions are then measured based on the largest benefit that has a greater than 50% likelihood of being realized. The Company recognizes interest and penalties related to income tax matters as income tax expense.
Segment Information	Segment Information Operating segments are components of an enterprise for which separate financial information is available and is evaluated regularly by the Company’s chief operating decision maker in deciding how to allocate resources and assessing performance. The Company’s chief operating decision maker is its Chief Executive Officer. The Chief Executive Officer reviews financial information presented on a consolidated basis, for purposes of allocating resources and evaluating financial performance. The Company has one business activity and there are no segment managers accountable for operations, operating results beyond revenue or gross profit, or plans for levels or components below the consolidated unit level. Accordingly, the Company has a single reporting segment.
Net Income Per Share Attributable to Common Stockholders	Net Income Per Share Attributable to Common Stockholders Basic and diluted net income per share attributable to Class A and Class B common stock is computed in conformity with the two-class method required for participating securities. The Company applies the two-class method to allocate earnings between common and other participating securities based on their participation rights. Prior to the conversion of preferred stock to common stock concurrent with the IPO in December 2020 and because the holders of the Company’s convertible preferred stock were entitled to participate in dividends, the Company allocated net income to common and preferred stock based on their respective rights to receive dividends, whether or not declared. Distributed and undistributed earnings allocated to participating securities are subtracted from net income in determining net income attributable to common stockholders. Basic net income per share is computed by dividing net income attributable to common stockholders by the weighted-average number of shares of our Class A and Class B common stock outstanding. The diluted net income per share attributable to common stockholders is computed by giving effect to all dilutive securities. Diluted net income per share attributable to common stockholders is computed by dividing the resulting net income attributable to common stockholders by the weighted-average number of fully diluted common shares outstanding. During the periods when there is a net loss attributable to common stockholders, potentially
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842), to increase transparency and comparability among organizations related to their leasing arrangements. This comprehensive new standard amends and supersedes existing lease accounting guidance and is intended to increase transparency and comparability among organizations by recognizing right-of-use (ROU) lease assets and lease liabilities on the balance sheet and requiring disclosure of key information about leasing arrangements. Lease expense continues to be recognized in a manner similar to legacy GAAP. The Company adopted the new lease standard on January 1, 2021 using the optional transition method to the modified retrospective approach. Under this transition provision, results for reporting periods beginning on January 1, 2021 are presented under Topic 842, while prior period amounts continue to be reported and disclosed in accordance with the Company’s historical accounting treatment under ASC Topic 840, Leases . To reduce the burden of adoption and ongoing compliance with Topic 842, a number of practical expedients and policy elections are available under the new guidance. The Company elected the "package of practical expedients" permitted under the transition guidance, which among other things, did not require reassessment of whether contracts entered into prior to adoption are or contain leases, and allowed carryforward of the historical lease classification for existing leases. The Company has not elected to adopt the “hindsight” practical expedient, and therefore will measure the ROU asset and lease liability using the remaining portion of the lease term at adoption on January 1, 2021. The Company made an accounting policy election under Topic 842 not to recognize right-of-use (ROU) assets and lease liabilities for leases with a term of twelve months or less. For all other leases, the Company recognizes ROU assets and lease liabilities based on the present value of lease payments over the lease term at the commencement date of the lease (or January 1, 2021 for existing leases upon the adoption of Topic 842). The ROU assets also include any initial direct costs incurred and lease payments made at or before the commencement date and are reduced by any lease incentives. The Company’s leases may include a non-lease component representing additional services transferred to the Company, such as common area maintenance for real estate. The Company made an accounting policy election to account for each separate lease component and the non-lease components associated with that lease component as a single lease component. As such, minimum lease payments include fixed payments for non-lease components within a lease agreement but exclude variable lease payments not dependent on an index or rate, such as common area maintenance, operating expenses, utilities, or other costs that are subject to fluctuation from period to period. Non-lease components that are variable in nature are recorded as variable lease expense in the period incurred. The Company uses its incremental borrowing rate to determine the present value of lease payments, as the Company’s leases do not have a readily determinable implicit discount rate. The incremental borrowing rate is the rate of interest the Company would have to pay to borrow on a collateralized basis over a similar term and amount in a similar economic environment. Judgement is applied in assessing factors such as Company-specific credit risk, lease term, nature and quality of the underlying collateral, currency, and economic environment in determining the incremental borrowing rate to apply to each lease. Adoption of Topic 842 resulted in the recording of ROU assets and lease liabilities related to the Company’s operating leases of approximately $2.8 million and $3.1 million, respectively, on January 1, 2021. The adoption of the new lease standard did not materially impact our consolidated net income or consolidated cash flows and did not result in a cumulative-effect adjustment to the opening balance of retained earnings. In June 2016, FASB issued ASU No. 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (ASU 2016-13). This update changes the accounting for recognizing impairments of financial assets, such that credit losses for certain types of financial instruments will be estimated based on expected losses. The update also modifies the impairment models for available-for-sale debt securities and for purchased financial assets with credit deterioration since their origination. The Company adopted ASU 2016-13 as of January 1, 2021. The standard did not have any material impact on its consolidated financial statements. In January 2017, the FASB issued ASU No. 2017-04, Intangibles—Goodwill and Other: Simplifying the Test for Goodwill Impairment (ASU 2017-04). ASU 2017-04 eliminates Step 2 from the goodwill impairment test which measures a goodwill impairment loss by comparing the implied fair value of a reporting unit’s goodwill with the carrying amount of that goodwill. Under ASU 2017-04, an entity should perform its annual or interim goodwill impairment test by comparing the fair value of the reporting unit with its carrying amount, and should recognize an impairment loss for the amount by which the carrying amount exceeds the reporting unit’s fair value, with the loss not exceeding the total amount of goodwill allocated to that reporting unit. The Company adopted ASU 2017-04 as of January 1, 2021. The standard did not have any material impact on its consolidated financial statements. In December 2019 the FASB issued ASU 2019-12—Simplifying the Accounting for Income Taxes (ASU 2019-12). ASU 2019-12 simplifies the accounting for income taxes by removing certain exceptions to general principles in Topic 740 and clarifies and amends existing guidance for clarity and consistent application.The Company adopted ASU 2019-12 as of January 1, 2021. The standard did not have a material impact on the condensed consolidated financial statements and related disclosures.

Basis of Presentation and Sum_3

Basis of Presentation and Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Accounts Receivable, Allowance for Credit Loss	The following table presents the changes in the allowance for credit losses (in thousands): December 31, 2021 2020 2019 Allowance for credit losses, beginning balance $ 1,989 $ 2,051 $ 1,784 Provision — 319 3,557 Write-offs (224) (381) (3,290) Allowance for credit losses, ending balance $ 1,765 $ 1,989 $ 2,051

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The following table sets forth the fair value of the Company’s financial assets and liabilities measured on a recurring basis by level within the fair value hierarchy (in thousands): December 31, 2021 Level I Level II Level III Total Financial Assets Money market funds $ 65,311 $ — $ — $ 65,311 Certificates of deposit — 5,942 — 5,942 Cash equivalents 65,311 5,942 — 71,253 Commercial paper — 50,954 — 50,954 U.S. Treasury and government debt securities — 26,167 — 26,167 Marketable securities — 77,121 — 77,121 Equity investment 5,948 — — 5,948 Non-current assets 5,948 — — 5,948 Total Financial Assets $ 71,259 $ 83,063 $ — $ 154,322 December 31, 2020 Level I Level II Level III Total Financial Assets Money market funds (1) $ 12,462 $ — $ — $ 12,462 Commercial paper (1) — 7,199 — 7,199 Cash equivalents 12,462 7,199 — 19,661 U.S. Treasury and government debt securities — 8,999 — 8,999 Commercial paper — 10,794 — 10,794 Marketable securities — 19,793 — 19,793 Total Financial Assets $ 12,462 $ 26,992 $ — $ 39,454 _______________ (1) The amounts were previously combined and presented as cash equivalents. Prior periods have been reclassified to conform with current period presentation.

Balance Sheet Components (Table

Balance Sheet Components (Tables)	12 Months Ended
	Dec. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Debt Securities, Available-for-sale	The following table summarizes the Company’s marketable securities by significant investment categories (in thousands): December 31, 2021 Amortized Cost Gross Unrealized Gains Gross Unrealized Loss Fair Value Commercial paper $ 50,954 $ — $ — $ 50,954 U.S. Treasury and government debt securities 26,203 — (36) 26,167 Total $ 77,157 $ — $ (36) $ 77,121 December 31, 2020 Amortized Cost Gross Unrealized Gains Gross Unrealized Loss Fair Value Commercial paper $ 10,794 $ — $ — $ 10,794 U.S. Treasury and government debt securities 8,998 1 — 8,999 Total $ 19,792 $ 1 $ — $ 19,793
Property, Plant and Equipment	Property, equipment and software, net consists of the following (in thousands): December 31, 2021 2020 Internal-use software $ 30,581 $ 24,513 Network hardware, computer equipment and software 92,561 62,764 Leasehold improvements 2,426 1,249 Furniture and fixtures 1,448 621 Property, equipment and software, gross 127,016 89,147 Less: accumulated depreciation and amortization (76,876) (59,103) Total property, equipment and software, net $ 50,140 $ 30,044
Schedule of Accounts Payable and Accrued Liabilities	Accounts payable consists of the following (in thousands): December 31, 2021 2020 Payable to publishers $ 235,440 $ 168,673 Trade payables 8,881 8,058 Total accounts payable $ 244,321 $ 176,731
Schedule of Accrued Liabilities	Accrued expenses consist of the following (in thousands): December 31, 2021 2020 Accrued compensation $ 17,271 $ 13,352 Accrued and other current liabilities 1,509 1,492 Total accrued expenses $ 18,780 $ 14,844

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2021
Leases [Abstract]
Lease, Cost	The components of lease expense are as follows: 2021 Operating lease cost $ 2,104 Finance lease cost - amortization of right-of-use assets 14 Finance lease cost - interest on lease liabilities 2 Total lease cost $ 2,120 Supplemental cash flow information related to leases is as follows: 2021 Cash paid for amounts included in measurement of lease liabilities: Operating cash outflows - payments on operating leases $ 2,283 Right-of-use assets obtained in exchange for new lease obligations: Operating leases $ 20,887 Finance leases 869
Assets and Liabilities, Lessee	Supplemental balance sheet information related to leases is as follows: 2021 Operating leases Operating lease right-of-use assets $ 21,613 Operating lease liabilities, current $ 3,864 Operating lease liabilities, non-current 17,842 Total operating lease liabilities $ 21,706 Finance leases Furniture and fixtures $ 869 Accumulated depreciation (14) Furniture and fixtures, net $ 855 Accrued liabilities $ 119 Other liabilities, non-current 741 Total finance lease liabilities $ 860 Weighted-average remaining lease term: Operating leases 6 years Finance leases 6.3 years Weighted-average discount rate: Operating leases 2.20 % Finance leases 2.24 %
Lessee, Operating Lease, Liability, Maturity	As of December 31, 2021, the maturities of lease liabilities under operating and finance leases were as follows: Year ending December 31, Operating leases Finance leases Total 2022 $ 4,298 $ 136 $ 4,434 2023 3,470 140 3,610 2024 3,459 145 3,604 2025 3,563 149 3,712 2026 3,670 153 3,823 Thereafter 4,750 200 4,950 Total minimum lease payments $ 23,210 $ 923 $ 24,133 Less: imputed interest (1,504) (63) (1,567) Total present value of lease liabilities $ 21,706 $ 860 $ 22,566
Schedule of Future Minimum Lease Payments for Capital Leases	A summary of the future minimum lease commitments, as determined under Topic 840, for all non-cancelable operating lease agreements were as follows as of December 31, 2020: 2021 $ 2,179 2022 1,031 2023 108 Total minimum lease commitments $ 3,318
Finance Lease, Liability, Fiscal Year Maturity	As of December 31, 2021, the maturities of lease liabilities under operating and finance leases were as follows: Year ending December 31, Operating leases Finance leases Total 2022 $ 4,298 $ 136 $ 4,434 2023 3,470 140 3,610 2024 3,459 145 3,604 2025 3,563 149 3,712 2026 3,670 153 3,823 Thereafter 4,750 200 4,950 Total minimum lease payments $ 23,210 $ 923 $ 24,133 Less: imputed interest (1,504) (63) (1,567) Total present value of lease liabilities $ 21,706 $ 860 $ 22,566

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Contractual Obligation, Fiscal Year Maturity	As of December 31, 2021, our outstanding contractual obligations with a term of 12 months or longer consist of the following (in thousands): Years ending December 31, Contractual Obligations 2022 10,506 2023 14,598 2024 6,540 2025 137 Total future minimum commitments, net $ 31,781

Stockholders_ Equity and Equi_2

Stockholders’ Equity and Equity Incentive Plans (Tables)	12 Months Ended
	Dec. 31, 2021
Equity [Abstract]
Disclosure of Share-based Compensation Arrangements by Share-based Payment Award	Options Outstanding Number of Shares Underlying Outstanding Options Weighted-Average Exercise Price Weighted Average Remaining Contractual Term (Years) Aggregate Intrinsic Value (in thousands) Outstanding — December 31, 2020 8,459,969 $ 2.53 6.83 $ 215,144 Options granted 660,466 $ 36.74 Options exercised (2,511,505) $ 2.16 Options canceled (66,419) $ 6.38 Options expired (160) $ 0.26 Outstanding — December 31, 2021 6,542,351 $ 6.08 6.95 $ 184,727 Vested and exercisable — December 31, 2021 4,341,907 $ 3.56 6.17 $ 132,770 RSUs Number of Shares Weighted-Average Grant Date Fair Value per Share Aggregate Intrinsic Value (in thousands) Unvested — December 31, 2020 — $ — $ — Granted 582,259 35.24 — Vested (79,838) 35.91 — Canceled/Forfeited (19,119) 32.69 — Unvested — December 31, 2021 483,302 $ 35.23 $ 17,025
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions	The Black-Scholes assumptions used to value the employee options at the grant dates are as follows: Year Ended December 31, 2021 2020 2019 Fair market value of common stock $39.75-$54.07 $3.20-$17.00 $3.01-$3.18 Expected term (in years) 5.8-6.7 5.7-6.4 5.2-6.6 Risk-free interest rate 0.6%-1.0% 0.3%-1.5% 1.4%-2.6% Expected volatility 51%-54% 50%-55% 52%-54% Dividend rate —% —% —% Year Ended December 31, 2021 Expected term (in years) 0.4-1.4 Risk-free interest rate 0.1% Expected volatility 60%-76% Dividend rate —%
Share-based Payment Arrangement, Expensed and Capitalized, Amount	The stock-based compensation expense by line item in the accompanying consolidated statements of operations is summarized as follows: December 31, 2021 2020 2019 Cost of revenue $ 825 $ 86 $ 26 Technology and development 2,232 599 402 Sales and marketing 5,176 1,101 684 General and administrative 5,874 1,777 890 Total stock-based compensation 14,107 3,563 2,002 Tax benefit from stock-based compensation (1,825) (493) (181) Total stock-based compensation, net of tax effect $ 12,282 $ 3,070 $ 1,821

Net Income Per Share Attribut_2

Net Income Per Share Attributable to Common Stockholders (Tables)	12 Months Ended
	Dec. 31, 2021
Earnings Per Share [Abstract]
Schedule of Earnings per Share, Basic, by Common Class, Including Two Class Method	The Company has two classes of common stock, Class A and Class B. 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. As the liquidation and dividend rights are identical, the undistributed earnings are allocated on a proportionate basis and the resulting net loss per share attributed to common stockholders will, therefore, be the same for both Class A and Class B common stock on an individual or combined basis. The following table sets forth the computation of the Company’s basic and diluted net income per share (in thousands, except share and per share data): Year Ended December 31, 2021 2020 2019 (in thousands, except share and per share data) Numerator: Net income $ 56,604 $ 26,613 $ 6,643 Less: Undistributed earnings allocated to participating securities — (20,187) (6,204) Net income attributable to common stockholders – basic $ 56,604 $ 6,426 $ 439 Denominator: Weighted average common shares outstanding – basic 50,184,455 12,642,293 10,036,983 Net income per share attributable to common stockholders – basic: $ 1.13 $ 0.51 $ 0.04 Numerator: Net income attributable to common stockholders - diluted $ 56,604 $ 7,929 $ 508 Denominator: Weighted average shares outstanding – basic 50,184,455 12,642,293 10,036,983 Options to purchase common stock 6,353,779 4,483,589 2,119,796 Restricted stock 29,662 — — Employee stock purchase plan shares 60,678 — — Warrants to purchase common stock — — 13,105 Weighted average shares outstanding – diluted 56,628,574 17,125,882 12,169,884 Net income per share attributable to common stockholders – diluted $ 1.00 $ 0.46 $ 0.04
Schedule of Earnings per Share, Diluted, by Common Class, Including Two Class Method	The Company has two classes of common stock, Class A and Class B. 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. As the liquidation and dividend rights are identical, the undistributed earnings are allocated on a proportionate basis and the resulting net loss per share attributed to common stockholders will, therefore, be the same for both Class A and Class B common stock on an individual or combined basis. The following table sets forth the computation of the Company’s basic and diluted net income per share (in thousands, except share and per share data): Year Ended December 31, 2021 2020 2019 (in thousands, except share and per share data) Numerator: Net income $ 56,604 $ 26,613 $ 6,643 Less: Undistributed earnings allocated to participating securities — (20,187) (6,204) Net income attributable to common stockholders – basic $ 56,604 $ 6,426 $ 439 Denominator: Weighted average common shares outstanding – basic 50,184,455 12,642,293 10,036,983 Net income per share attributable to common stockholders – basic: $ 1.13 $ 0.51 $ 0.04 Numerator: Net income attributable to common stockholders - diluted $ 56,604 $ 7,929 $ 508 Denominator: Weighted average shares outstanding – basic 50,184,455 12,642,293 10,036,983 Options to purchase common stock 6,353,779 4,483,589 2,119,796 Restricted stock 29,662 — — Employee stock purchase plan shares 60,678 — — Warrants to purchase common stock — — 13,105 Weighted average shares outstanding – diluted 56,628,574 17,125,882 12,169,884 Net income per share attributable to common stockholders – diluted $ 1.00 $ 0.46 $ 0.04
Schedule of Antidilutive Securities Excluded from Computation of Earnings per Share	The following weighted-average outstanding shares of common stock equivalents were excluded from the computation of diluted net income per share attributable to common stockholders for the periods presented because including them would have been anti-dilutive: Year Ended December 31, 2021 2020 2019 Options to purchase common stock 671,244 846,481 3,359,458 Common stock issuable upon conversion of convertible preferred stock — — 33,410,274 Total excludable from net income per share attributable to common stockholders – diluted 671,244 846,481 36,769,732

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Schedule of Income before Income Tax, Domestic and Foreign	The following table presents domestic and foreign components of income (loss) before income taxes for the periods presented (in thousands): December 31, 2021 2020 2019 Domestic $ 61,822 $ 28,169 $ 6,995 International 2,981 3,411 2,227 Income before provision for income taxes $ 64,803 $ 31,580 $ 9,222
Schedule of Components of Income Tax Expense (Benefit)	The income tax (benefit) provision is composed of the following (in thousands): December 31, 2021 2020 2019 Current provisions for income taxes: Federal $ 2,437 $ 360 $ 1,639 State 714 240 58 Foreign 295 1,434 689 Total current tax expense 3,446 2,034 2,386 Deferred tax expense: Federal $ 4,513 $ 1,845 $ 254 State 251 1,170 4 Foreign (11) (82) (65) Total deferred tax expense 4,753 2,933 193 Total provision for income taxes $ 8,199 $ 4,967 $ 2,579
Schedule of Effective Income Tax Rate Reconciliation	The following table presents a reconciliation of the statutory federal rate and the Company’s effective tax rate for the periods presented: December 31, 2021 2020 2019 Statutory federal income tax rate 21.00 % 21.00 % 21.00 % State after-tax rate 1.49 4.47 0.67 Stock options (10.38) (6.79) 5.48 Research credit (1.37) (2.04) (2.85) Transfer pricing reserve (1.26) 1.32 (0.68) Foreign rate differential 0.73 0.61 2.37 Foreign derived intangible income (0.48) (3.26) (7.89) Section 162(m) limitation 2.49 — — Other 0.42 0.42 9.86 12.64 % 15.73 % 27.96 %
Schedule of Deferred Tax Assets and Liabilities	Deferred income taxes reflect the net tax effects of temporary differences between carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. The following table presents the significant components of the Company’s deferred tax assets and liabilities for the periods presented (in thousands): December 31, 2021 2020 2019 Deferred tax assets: Net operating loss carryforwards $ 56 $ 124 $ 194 Accruals and allowances 1,104 614 784 Tax credits 1,396 1,631 1,064 Stock-based compensation 3,171 2,045 1,749 Intangibles assets 1,010 1,106 1,202 Lease obligation 5,226 — — Other 808 1,101 967 Valuation allowance (1,396) (1,372) — Total deferred tax assets 11,375 5,249 5,960 Deferred tax liabilities: Property, equipment, and software (8,316) (4,995) (3,003) Goodwill (749) (653) (562) Prepaid expense (1,365) (400) (256) Right-of-use asset (5,201) — — Unrealized gain on equity investment (1,296) — — Total deferred tax liabilities (16,927) (6,048) (3,821) Net deferred income tax asset (liabilities) $ (5,552) $ (799) $ 2,139
Summary of Income Tax Contingencies	The activity related to the unrecognized income tax benefits is as follows (in thousands): Year Ended December 31, 2021 2020 2019 Gross unrecognized income tax benefits — beginning balance $ 3,208 $ 2,369 $ 2,210 Increases related to tax positions taken during the current year 649 951 541 Decreases related to tax positions taken during prior years (1,493) (112) (382) Increases related to tax positions taken during the prior years — — — Gross unrecognized income tax benefits — ending balance $ 2,364 $ 3,208 $ 2,369

Segment Reporting (Tables)

Segment Reporting (Tables)	12 Months Ended
	Dec. 31, 2021
Segment Reporting [Abstract]
Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas	The following table represents total revenue by geographic area based on the publisher’s billing address (in thousands): Year Ended December 31, 2021 2020 2019 United States $ 139,049 $ 96,886 $ 77,314 EMEA 62,531 34,156 23,642 APAC 20,910 15,087 10,988 Rest of the world 4,418 2,619 1,927 Total $ 226,908 $ 148,748 $ 113,871 The Company’s long-lived assets, net by geographic area are summarized as follows (in thousands): Year Ended December 31, 2021 2020 United States $ 42,059 $ 24,580 Rest of the world 8,081 5,464 Total $ 50,140 $ 30,044

Basis of Presentation and Sum_4

Basis of Presentation and Summary of Significant Accounting Policies - Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, beginning balance	$ 1,989	$ 2,051	$ 1,784
Provision for doubtful accounts	0	319	3,557
Write-offs	(224)	(381)	(3,290)
Allowance for credit losses, ending balance	$ 1,765	$ 1,989	$ 2,051

Basis of Presentation and Sum_5

Basis of Presentation and Summary of Significant Accounting Policies - Internal Use Software Development Costs (Details) - Internal-use software	12 Months Ended
	Dec. 31, 2021
Minimum
Property, Plant and Equipment [Line Items]
Finite-lived intangible asset, useful life	2 years
Maximum
Property, Plant and Equipment [Line Items]
Finite-lived intangible asset, useful life	5 years

Basis of Presentation and Sum_6

Basis of Presentation and Summary of Significant Accounting Policies - Advertising Costs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Accounting Policies [Abstract]
Advertising expense	$ 0.5	$ 0.5	$ 0.3

Basis of Presentation and Sum_7

Basis of Presentation and Summary of Significant Accounting Policies - Foreign Currency Translation (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Accounting Policies [Abstract]
Foreign Currency Transaction (gain) loss, unrealized	$ (0.1)	$ 0.6	$ 0.4

Basis of Presentation and Sum_8

Basis of Presentation and Summary of Significant Accounting Policies - Concentration Risk Percentage (Details) - Customer Concentration Risk - Accounts Receivable	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
One Publisher
Concentration Risk [Line Items]
Concentration risk, percentage	20.00%	28.00%	17.00%
Buyer One
Concentration Risk [Line Items]
Concentration risk, percentage	29.00%	33.00%
Buyer Two
Concentration Risk [Line Items]
Concentration risk, percentage	19.00%	14.00%
Buyer Three
Concentration Risk [Line Items]
Concentration risk, percentage		13.00%
Buyer Four
Concentration Risk [Line Items]
Concentration risk, percentage		11.00%

Basis of Presentation and Sum_9

Basis of Presentation and Summary of Significant Accounting Policies - Recently Adopted Accounting Pronouncements (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Jan. 01, 2021	Dec. 31, 2020
Accounting Policies [Abstract]
Operating lease right-of-use assets	$ 21,613	$ 2,800	$ 0
Total operating lease liabilities	$ 21,706	$ 3,100

Fair Value Measurements - Finan

Fair Value Measurements - Financial Assets and Liabilities (Details) - Fair Value, Recurring - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
U.S. Treasury and government debt securities	$ 77,121	$ 19,793
Equity investment	5,948
Non-current assets	5,948
Total Financial Assets	154,322	39,454
Level I
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
U.S. Treasury and government debt securities	0	0
Equity investment	5,948
Non-current assets	5,948
Total Financial Assets	71,259	12,462
Level II
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
U.S. Treasury and government debt securities	77,121	19,793
Equity investment	0
Non-current assets	0
Total Financial Assets	83,063	26,992
Level III
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
U.S. Treasury and government debt securities	0	0
Equity investment	0
Non-current assets	0
Total Financial Assets	0	0
Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
U.S. Treasury and government debt securities	50,954	8,999
Commercial paper | Level I
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
U.S. Treasury and government debt securities	0	0
Commercial paper | Level II
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
U.S. Treasury and government debt securities	50,954	8,999
Commercial paper | Level III
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
U.S. Treasury and government debt securities	0	0
U.S. Treasury and government debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
U.S. Treasury and government debt securities	26,167	10,794
U.S. Treasury and government debt securities | Level I
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
U.S. Treasury and government debt securities	0	0
U.S. Treasury and government debt securities | Level II
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
U.S. Treasury and government debt securities	26,167	10,794
U.S. Treasury and government debt securities | Level III
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
U.S. Treasury and government debt securities	0	0
Money Market Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	65,311	12,462
Money Market Funds | Level I
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	65,311	12,462
Money Market Funds | Level II
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Money Market Funds | Level III
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Certificates of Deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	5,942	7,199
Certificates of Deposit | Level I
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Certificates of Deposit | Level II
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	5,942	7,199
Certificates of Deposit | Level III
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	71,253	19,661
Cash Equivalents | Level I
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	65,311	12,462
Cash Equivalents | Level II
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	5,942	7,199
Cash Equivalents | Level III
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	$ 0	$ 0

Balance Sheet Components - Summ

Balance Sheet Components - Summary of Marketable Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 77,157	$ 19,792
Gross Unrealized Gains	0	1
Gross Unrealized Loss	(36)	0
Marketable securities	77,121	19,793
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	50,954	10,794
Gross Unrealized Gains	0	0
Gross Unrealized Loss	0	0
Marketable securities	50,954	10,794
U.S. Treasury and government debt securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	26,203	8,998
Gross Unrealized Gains	0	1
Gross Unrealized Loss	(36)	0
Marketable securities	$ 26,167	$ 8,999

Balance Sheet Components - Sche

Balance Sheet Components - Schedule of Property, Equipment and Software, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Property, equipment and software, gross	$ 127,016	$ 89,147
Less: accumulated depreciation and amortization	(76,876)	(59,103)
Total property, equipment and software, net	50,140	30,044
Internal-use software
Property, Plant and Equipment [Line Items]
Property, equipment and software, gross	30,581	24,513
Network hardware, computer equipment and software
Property, Plant and Equipment [Line Items]
Property, equipment and software, gross	92,561	62,764
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, equipment and software, gross	2,426	1,249
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property, equipment and software, gross	$ 1,448	$ 621

Balance Sheet Components - Narr

Balance Sheet Components - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Depreciation and amortization	$ 15,700,000	$ 9,800,000	$ 6,900,000
Capitalized computer software additions	10,300,000	7,300,000	6,000,000
Capitalized computer software, impairments	0	0	700,000
Internal-use software
Property, Plant and Equipment [Line Items]
Amortization	$ 7,400,000	$ 5,900,000	$ 5,400,000

Balance Sheet Components - Sc_2

Balance Sheet Components - Schedule of Accounts Payable (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Payable to publishers	$ 235,440	$ 168,673
Trade payables	8,881	8,058
Total accounts payable	$ 244,321	$ 176,731

Balance Sheet Components - Sc_3

Balance Sheet Components - Schedule of Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accrued compensation	$ 17,271	$ 13,352
Accrued and other current liabilities	1,509	1,492
Total accrued expenses	$ 18,780	$ 14,844

Loan and Security Agreement (De

Loan and Security Agreement (Details) - Revolving Credit Facility - Silicon Valley Bank $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)	Dec. 31, 2021
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 25
Line of credit facility, borrowing capacity, percentage of eligible accounts receivable, net,	80000000.00%
Debt instrument, interest rate	3.25%
Line of credit facility, unused capacity, commitment fee percentage	0.40%
Line of credit facility, borrowing capacity, unused capacity fee, closing balance threshold	$ 5
Debt instrument, covenant, quick ratio, minimum		1

Leases - Narrative (Details)

Leases - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Lessee, Lease, Description [Line Items]
Operating Lease, Expense	$ 2.5	$ 2.5	$ 2.6
Sublease Income		$ 0.4	$ 0.6
Office Equipment
Lessee, Lease, Description [Line Items]
Lease term	7 years
Lease term, extension period	10 years
Minimum
Lessee, Lease, Description [Line Items]
Lease term	2 years
Maximum
Lessee, Lease, Description [Line Items]
Lease term	10 years

Leases - Lease Cost (Details)

Leases - Lease Cost (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021USD ($)
Leases [Abstract]
Operating Lease, Cost	$ 2,104
Finance Lease, Right-of-Use Asset, Amortization	14
Finance Lease, Interest Expense	2
Lease, Cost	$ 2,120

Leases - Supplemental Cash Flow

Leases - Supplemental Cash Flows (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021USD ($)
Cash paid for amounts included in measurement of lease liabilities:
Operating cash outflows - payments on operating leases	$ 2,283
Right-of-use assets obtained in exchange for new lease obligations:
Operating leases	20,887
Finance leases	$ 869

Leases - Supplemental Balance S

Leases - Supplemental Balance Sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Jan. 01, 2021	Dec. 31, 2020
Operating leases
Operating lease right-of-use assets	$ 21,613	$ 2,800	$ 0
Operating lease liabilities, current	3,864		0
Operating lease liabilities, non-current	17,842		$ 0
Total operating lease liabilities	21,706	$ 3,100
Finance leases
Furniture and fixtures	869
Accumulated depreciation	(14)
Furniture and fixtures, net	855
Accrued liabilities	119
Other liabilities, non-current	$ 741
Finance Lease, Liability, Statement of Financial Position [Extensible Enumeration]	Liabilities		Liabilities
Total finance lease liabilities	$ 860
Weighted-average remaining lease term:
Operating leases	6 years
Finance leases	6 years 3 months 18 days
Weighted-average discount rate:
Operating leases	2.20%
Finance leases	2.24%
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Property, equipment and software - net		Property, equipment and software - net

Leases - Lease Maturity (Detail

Leases - Lease Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Jan. 01, 2021
Operating leases
2022	$ 4,298
2023	3,470
2024	3,459
2025	3,563
2026	3,670
Thereafter	4,750
Total minimum lease payments	23,210
Less: imputed interest	(1,504)
Total operating lease liabilities	21,706	$ 3,100
Finance leases
2022	136
2023	140
2024	145
2025	149
2026	153
Thereafter	200
Total minimum lease payments	923
Less: imputed interest	(63)
Total finance lease liabilities	860
Total
2022	4,434
2023	3,610
2024	3,604
2025	3,712
2026	3,823
Thereafter	4,950
Total minimum lease payments	24,133
Less: imputed interest	(1,567)
Total present value of lease liabilities	$ 22,566

Leases - Future Minimum Lease P

Leases - Future Minimum Lease Payments Under Topic 840 (Details) $ in Thousands	Dec. 31, 2020USD ($)
Leases [Abstract]
2021	$ 2,179
2022	1,031
2023	108
Total minimum lease commitments	$ 3,318

Commitments and Contingencies -

Commitments and Contingencies - Future Minimum Commitments (Details) $ in Thousands	Dec. 31, 2021USD ($)
Contractual Obligations
2022	$ 10,506
2023	14,598
2024	6,540
2025	137
Total future minimum commitments, net	$ 31,781

Commitments and Contingencies_2

Commitments and Contingencies - Narrative (Details) $ in Millions	Dec. 31, 2021USD ($)
Irrevocable Letters of Credit due July 2028
Long-term Purchase Commitment [Line Items]
Letters of credit outstanding, amount	$ 3.5
Irrevocable Letters of Credit due June 2022
Long-term Purchase Commitment [Line Items]
Letters of credit outstanding, amount	$ 0.7

Convertible Preferred Stock (De

Convertible Preferred Stock (Details) - USD ($) $ / shares in Units, $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 11, 2020	Dec. 31, 2019	Dec. 31, 2018
Preferred Units [Line Items]
Preferred stock shares authorized	10,000,000	10,000,000	10,000,000
Preferred stock par value (in usd per share)	$ 0.0001	$ 0.0001	$ 0.0001
Common Class B
Preferred Units [Line Items]
Convertible preferred stock, shares issued upon conversion			33,443,969
Convertible Preferred Stock
Preferred Units [Line Items]
Temporary equity, carrying amount, attributable to parent	$ 0	$ 0	$ 61,200	$ 61,216	$ 60,820

Stockholders_ Notes Receivabl_2

Stockholders’ Notes Receivable and Redeemable Common Stock (Details) - USD ($) $ in Thousands, shares in Millions	1 Months Ended
	Aug. 31, 2018	Dec. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Dec. 31, 2019	Dec. 31, 2018
Class of Stock [Line Items]
Temporary equity, common stock, shares issued	1.6
Temporary equity, incremental expense	$ 1,000
Redeemable Common Stock
Class of Stock [Line Items]
Temporary equity, carrying amount, attributable to parent		$ 0	$ 0	$ 19,000	$ 19,025	$ 19,025
2.42% due August 2021 | Notes Payable, Other Payables
Class of Stock [Line Items]
Debt instrument, face amount	$ 4,000
Debt instrument, interest rate	2.42%

Stockholders_ Equity and Equi_3

Stockholders’ Equity and Equity Incentive Plans - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 11, 2020	Nov. 30, 2020
Class of Stock [Line Items]
Common shares reserved for issuance	6,386,698
Share-based compensation arrangement by share-based payment award, options, exercises in period, intrinsic value	$ 80.7	$ 15.7	$ 0.1
Share-based compensation arrangement by share-based payment award, options, grants in period, weighted average grant date fair value	$ 20.30	$ 4.96	$ 1.65
Discount from market price, purchase date	85.00%
Amount withheld for employee stock purchase plan	$ 0.3
Share-based Payment Arrangement, Option
Class of Stock [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	4 years
Share-based payment arrangement, nonvested award, option, cost not yet recognized, amount		$ 17
Share-based payment arrangement, nonvested award, cost not yet recognized, period for recognition	2 years 8 months 8 days
Restricted Stock Units (RSUs)
Class of Stock [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	4 years
Share-based payment arrangement, nonvested award, cost not yet recognized, period for recognition	3 years 4 months 2 days
Share-based payment arrangement, nonvested award, excluding option, cost not yet recognized, amount	$ 15.7
Employee Stock
Class of Stock [Line Items]
Common shares reserved for issuance	713,475
Share-based payment arrangement, nonvested award, cost not yet recognized, period for recognition	4 months 28 days
Share-based payment arrangement, nonvested award, excluding option, cost not yet recognized, amount	$ 1.4
Common Class A
Class of Stock [Line Items]
Common stock shares authorized	1,000,000,000	1,000,000,000		1,000,000,000
Common stock par value (in usd per share)	$ 0.0001	$ 0.0001		$ 0.0001
Issuance of common stock related to employee stock purchase plan (in shares)	276,406
Common Class A | Employee Stock
Class of Stock [Line Items]
Common shares reserved for issuance					500,000
Number of shares authorized	7,500,000
Common Class B
Class of Stock [Line Items]
Common stock shares authorized	1,000,000,000	1,000,000,000		1,000,000,000
Common stock par value (in usd per share)	$ 0.0001	$ 0.0001		$ 0.0001

Stockholders_ Equity and Equi_4

Stockholders’ Equity and Equity Incentive Plans - Summary of Stock Option Activity and Related Information (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Number of Shares Underlying Outstanding Options
Beginning balance (in shares)	8,459,969
Options granted (in shares)	660,466
Options exercised (in shares)	(2,511,505)
Options canceled (in shares)	(66,419)
Options expired (in shares)	(160)
Ending balance (in shares)	6,542,351	8,459,969
Vested (in shares)	4,341,907
Weighted-Average Exercise Price
Beginning balance (in usd per share)	$ 2.53
Options granted (in usd per share)	36.74
Options exercised (in usd per share)	2.16
Options canceled (in usd per share)	6.38
Options expired (in usd per share)	0.26
Ending balance (in usd per share)	6.08	$ 2.53
Vested (in usd per share)	$ 3.56
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Weighted average remaining contractual term (years)	6 years 11 months 12 days	6 years 9 months 29 days
Weighted average remaining contractual term vested (in years)	6 years 2 months 1 day
Aggregate intrinsic value, awards outstanding	$ 184,727	$ 215,144
Aggregate intrinsic value, vested	$ 132,770

Stockholders_ Equity and Equi_5

Stockholders’ Equity and Equity Incentive Plans - Weighted-Average Assumptions (Details) - $ / shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Dividend rate	0.00%	0.00%	0.00%
ESPP
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Risk-free interest rate	0.10%
Dividend rate	0.00%
Minimum
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Fair market value of common stock (in usd per share)	$ 39.75	$ 3.20	$ 3.01
Expected term (in years)	5 years 9 months 18 days	5 years 8 months 12 days	5 years 2 months 12 days
Risk-free interest rate	0.60%	0.30%	1.40%
Expected volatility	51.00%	50.00%	52.00%
Minimum | ESPP
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Expected term (in years)	4 months 24 days
Expected volatility	60.00%
Maximum
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Fair market value of common stock (in usd per share)	$ 54.07	$ 17	$ 3.18
Expected term (in years)	6 years 8 months 12 days	6 years 4 months 24 days	6 years 7 months 6 days
Risk-free interest rate	1.00%	1.50%	2.60%
Expected volatility	54.00%	55.00%	54.00%
Maximum | ESPP
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Expected term (in years)	1 year 4 months 24 days
Expected volatility	76.00%

Stockholders_ Equity and Equi_6

Stockholders’ Equity and Equity Incentive Plans - Summary of Restricted Stock Units and Related Information (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021USD ($)$ / sharesshares
Aggregate Intrinsic Value (in thousands)
Aggregate intrinsic value, unvested | $	$ 17,025
Restricted Stock Units (RSUs)
Number of Shares Underlying Outstanding Options
Unvested beginning balance (in shares) | shares	0
Granted (in shares) | shares	582,259
Vested (in shares) | shares	(79,838)
Canceled/Forfeited (in shares) | shares	(19,119)
Unvested ending balance (in shares) | shares	483,302
Weighted-Average Exercise Price
Unvested beginning balance (in usd per share) | $ / shares	$ 0
Granted (in usd per share) | $ / shares	35.24
Vested (in usd per share) | $ / shares	35.91
Canceled/Forfeited (in usd per share) | $ / shares	32.69
Unvested ending balance (in usd per share) | $ / shares	$ 35.23

Stockholders_ Equity and Equi_7

Stockholders’ Equity and Equity Incentive Plans - Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	$ 14,107	$ 3,563	$ 2,002
Tax benefit from stock-based compensation	(1,825)	(493)	(181)
Total stock-based compensation, net of tax effect	12,282	3,070	1,821
Cost of revenue
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	825	86	26
Technology and development
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	2,232	599	402
Sales and marketing
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	5,176	1,101	684
General and administrative
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	$ 5,874	$ 1,777	$ 890

Net Income Per Share Attribut_3

Net Income Per Share Attributable to Common Stockholders - Basic and Diluted Net Income per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Numerator:
Net income	$ 56,604	$ 26,613	$ 6,643
Less: Undistributed earnings allocated to participating securities	0	(20,187)	(6,204)
Net income attributable to common stockholders – basic	$ 56,604	$ 6,426	$ 439
Denominator:
Weighted average common shares outstanding – basic	50,184,455	12,642,293	10,036,983
Net income per share attributable to common stockholders – basic: (in usd per share)	$ 1.13	$ 0.51	$ 0.04
Numerator:
Net income attributable to common stockholders - diluted	$ 56,604	$ 7,929	$ 508
Denominator:
Weighted average common shares outstanding – basic	50,184,455	12,642,293	10,036,983
Options to purchase common stock (in shares)	6,353,779	4,483,589	2,119,796
Restricted stock (in shares)	29,662	0	0
Employee stock purchase plan shares	60,678	0	0
Warrants to purchase common stock (in shares)	0	0	13,105
Weighted average shares outstanding – diluted	56,628,574	17,125,882	12,169,884
Net income per share attributable to common stockholders – diluted (in usd per share)	$ 1	$ 0.46	$ 0.04

Net Income Per Share Attribut_4

Net Income Per Share Attributable to Common Stockholders - Schedule of Antidilutive Securities Excluded from Computation of Earnings per Share (Details) - shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Total excludable from net income per share attributable to common stockholders – diluted	671,244	846,481	36,769,732
Options to purchase common stock
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Total excludable from net income per share attributable to common stockholders – diluted	671,244	846,481	3,359,458
Common stock issuable upon conversion of convertible preferred stock
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Total excludable from net income per share attributable to common stockholders – diluted	0	0	33,410,274

Income Taxes - Income Before Pr

Income Taxes - Income Before Provision for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Domestic	$ 61,822	$ 28,169	$ 6,995
International	2,981	3,411	2,227
Income before provision for income taxes	$ 64,803	$ 31,580	$ 9,222

Income Taxes - Provision for In

Income Taxes - Provision for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Current provisions for income taxes:
Federal	$ 2,437	$ 360	$ 1,639
State	714	240	58
Foreign	295	1,434	689
Total current tax expense	3,446	2,034	2,386
Deferred tax expense:
Federal	4,513	1,845	254
State	251	1,170	4
Foreign	(11)	(82)	(65)
Deferred income taxes	4,753	2,933	193
Provision for income taxes	$ 8,199	$ 4,967	$ 2,579

Income Taxes - Effective Income

Income Taxes - Effective Income After-Tax Rate (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Statutory federal income tax rate	21.00%	21.00%	21.00%
State after-tax rate	1.49%	4.47%	0.67%
Stock options	(10.38%)	(6.79%)	5.48%
Research credit	(1.37%)	(2.04%)	(2.85%)
Transfer pricing reserve	(1.26%)	1.32%	(0.68%)
Foreign rate differential	0.73%	0.61%	2.37%
Foreign derived intangible income	(0.48%)	(3.26%)	(7.89%)
Section 162(m) limitation	2.49%	0.00%	0.00%
Other	0.42%	0.42%	9.86%
Effective income tax rate reconciliation, percent	12.64%	15.73%	27.96%

Income Taxes - Deferred Income

Income Taxes - Deferred Income Tax Assets (Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Net operating loss carryforwards	$ 56	$ 124	$ 194
Accruals and allowances	1,104	614	784
Tax credits	1,396	1,631	1,064
Stock-based compensation	3,171	2,045	1,749
Intangibles assets	1,010	1,106	1,202
Lease obligation	5,226	0	0
Other	808	1,101	967
Valuation allowance	(1,396)	(1,372)	0
Total deferred tax assets	11,375	5,249	5,960
Deferred tax liabilities:
Property, equipment, and software	(8,316)	(4,995)	(3,003)
Goodwill	(749)	(653)	(562)
Prepaid expense	(1,365)	(400)	(256)
Right-of-use asset	(5,201)	0	0
Unrealized gain on equity investment	(1,296)	0	0
Total deferred tax liabilities	(16,927)	(6,048)	(3,821)
Net deferred income tax asset (liabilities)			$ 2,139
Net deferred income tax asset (liabilities)	$ (5,552)	$ (799)

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Tax Credit Carryforward [Line Items]
Unrecognized tax benefits, interest on income taxes accrued	$ 0.1	$ 0.3
Unrecognized tax benefits that would impact effective tax rate	2.4
Research Tax Credit Carryforward
Tax Credit Carryforward [Line Items]
Tax credit carryforward, amount	2.9
State and Local Jurisdiction
Tax Credit Carryforward [Line Items]
Operating loss carryforwards	$ 1.9

Income Taxes - Unrecognized Inc

Income Taxes - Unrecognized Income Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Gross unrecognized income tax benefits — beginning balance	$ 3,208	$ 2,369	$ 2,210
Increases related to tax positions taken during the current year	649		541
Increases related to tax positions taken during the current year		951
Decreases related to tax positions taken during prior years	(1,493)	(112)	(382)
Increases related to tax positions taken during the prior years	0	0	0
Gross unrecognized income tax benefits — ending balance	$ 2,364	$ 3,208	$ 2,369

Segment Reporting (Details)

Segment Reporting (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 226,908	$ 148,748	$ 113,871
Long-lived assets	50,140	30,044
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	139,049	96,886	77,314
Long-lived assets	42,059	24,580
EMEA
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	62,531	34,156	23,642
APAC
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	20,910	15,087	10,988
Rest of the world
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	4,418	2,619	$ 1,927
Long-lived assets	$ 8,081	$ 5,464

401(k) Plan - Narrative (Detail

401(k) Plan - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Retirement Benefits [Abstract]
Defined contribution plan, maximum annual contributions per employee, percent	100.00%
Defined contribution plan, employer discretionary contribution amount	$ 0	$ 0