Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (loss)	Accumulated Deficit
Redeemable Convertible Preferred Stock Beginning Balance (in shares) at Dec. 31, 2018	287,216,434
Redeemable Convertible Preferred Stock Beginning Balance at Dec. 31, 2018	$ 114,842
Redeemable Convertible Preferred Stock
Issuance of Series E-1 redeemable convertible preferred stock (in shares)	38,552,483
Issuance of Series E-1 redeemable convertible preferred stock	$ 142,990
Conversion of redeemable convertible preferred stock to common stock upon initial public offering (in shares)	(11,074,661)
Conversion of redeemable convertible preferred stock to common stock upon initial public offering	$ 13,767
Deemed dividend upon the exchange of Series A and Series C redeemable convertible preferred stock for Series E redeemable convertible preferred stock	$ 64,149
Redeemable Convertible Preferred Stock Ending Balance (in shares) at Dec. 31, 2019	336,843,578
Redeemable Convertible Preferred Stock Ending Balance at Dec. 31, 2019	$ 335,748
Balance at the beginning of the period (in shares) at Dec. 31, 2018		121,411,803
Balance at the beginning of the period at Dec. 31, 2018	(84,907)	$ 12	$ 2,870	$ (1)	$ (87,788)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversion of redeemable convertible preferred stock to common stock upon initial public offering (in shares)		(11,074,661)
Conversion of redeemable convertible preferred stock to common stock upon initial public offering	(13,767)		(13,767)
Issuance of common stock upon exercise of vested options (in shares)		7,767,038
Issuance of common stock upon exercise of vested options	515		515
Issuance of common stock upon early exercise of unvested options (in shares)		762,440
Deemed dividend upon the exchange of Series A and Series C redeemable convertible preferred stock for Series E redeemable convertible preferred stock	(64,149)		(4,308)		(59,841)
Repurchase of early exercised stock options (in shares)		(436,589)
Vesting of early exercised stock options	298		298
Share-based compensation expense	21,757		21,757
Change in other comprehensive income (loss)	47			47
Net loss	(58,200)				(58,200)
Balance at the end of the period (in shares) at Dec. 31, 2019		118,430,031
Balance at the end of the period at Dec. 31, 2019	$ (198,406)	$ 12	7,365	46	(205,829)
Redeemable Convertible Preferred Stock
Issuance of Series E-1 redeemable convertible preferred stock (in shares)	20,989,756
Issuance of Series E-1 redeemable convertible preferred stock	$ 166,942
Conversion of redeemable convertible preferred stock to common stock upon initial public offering (in shares)	(5,988,994)
Conversion of redeemable convertible preferred stock to common stock upon initial public offering	$ (809)
Redeemable Convertible Preferred Stock Ending Balance (in shares) at Dec. 31, 2020	351,844,340
Redeemable Convertible Preferred Stock Ending Balance at Dec. 31, 2020	$ 501,881
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversion of redeemable convertible preferred stock to common stock upon initial public offering (in shares)		(5,988,994)
Conversion of redeemable convertible preferred stock to common stock upon initial public offering	(809)	$ (1)	(808)
Issuance of common stock upon exercise of vested options (in shares)		5,236,999
Issuance of common stock upon exercise of vested options	2,472		2,472
Repurchase of early exercised stock options (in shares)		(190,370)
Issuance of common stock net settlement of restricted stock units (in shares)		847,184
Vesting of early exercised stock options	742		742
Vesting of common stock warrants	171		171
Share-based compensation expense	28,211		28,211
Change in other comprehensive income (loss)	(21)			(21)
Net loss	(47,695)				(47,695)
Balance at the end of the period (in shares) at Dec. 31, 2020		130,312,838
Balance at the end of the period at Dec. 31, 2020	$ (213,717)	$ 13	39,769	25	(253,524)
Redeemable Convertible Preferred Stock
Conversion of redeemable convertible preferred stock to common stock upon initial public offering (in shares)	(351,844,340)
Conversion of redeemable convertible preferred stock to common stock upon initial public offering	$ (501,881)
Redeemable Convertible Preferred Stock Ending Balance (in shares) at Dec. 31, 2021	0
Redeemable Convertible Preferred Stock Ending Balance at Dec. 31, 2021	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon Initial public offering, net of issuance costs (in shares)		52,272,727
Issuance of common stock upon initial public offering, net of issuance costs	1,312,338	$ 7	1,312,331
Conversion of redeemable convertible preferred stock to common stock upon initial public offering (in shares)		(351,844,340)
Conversion of redeemable convertible preferred stock to common stock upon initial public offering	(501,881)	$ (34)	(501,847)
Reclassification of redeemable convertible preferred stock warrant liabilities to common stock and additional paid-in capital upon initial public offering	5,438		5,438
Issuance of common stock upon exercise of vested options (in shares)		4,277,344
Issuance of common stock upon exercise of vested options	4,969		4,969
Issuance of common stock under employee stock purchase plan		153,905
Issuance of common stock under employee stock purchase plan	3,201		3,201
Repurchase of early exercised stock options (in shares)		(85,870)
Issuance of common stock net settlement of restricted stock units (in shares)		1,736,212
Issuance of common stock upon net settlement of restricted stock units	(23,552)		(23,552)
Issuance of common stock upon exercise of common stock warrants (in shares)		872,022
Issuance of common stock upon exercise of common stock warrants	60
Vesting of common stock warrants	6,332		6,332
Share-based compensation expense	142,660		142,660
Change in other comprehensive income (loss)	(2,255)			(2,255)
Net loss	(163,929)				(163,929)
Balance at the end of the period (in shares) at Dec. 31, 2021		541,383,518
Balance at the end of the period at Dec. 31, 2021	$ 1,573,426	$ 54	$ 1,993,055	$ (2,230)	$ (417,453)