Net Income (Loss) Per Share - Summary of Antidilutive Potential Common Shares (Details) - shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive potential common shares (in shares)	4,091,075	139,124,963	126,226,359
Convertible preferred stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive potential common shares (in shares)	0	109,090,908	109,090,908
Stock options exercised for promissory notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive potential common shares (in shares)	2,884,999	8,022,499	5,760,000
Early exercised stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive potential common shares (in shares)	487,000	19,800	11,337
Unvested RSAs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive potential common shares (in shares)	181,737	1,236,771	3,924,414
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive potential common shares (in shares)	0	20,754,985	7,439,700
Unvested RSU
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive potential common shares (in shares)	291,093	0	0
ESPP
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive potential common shares (in shares)	246,246	0	0