Stock-Based Compensation - Summary of Activity under Stock Option Plans (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)	4,858,590
Granted (in shares)	1,500,000
Exercised (in shares)	(2,035,709)
Forfeited and canceled (in shares)	(58,813)
Ending balance (in shares)	4,264,068	4,858,590
Vested and exercisable (in shares)	2,542,329
Vested and expected to vest (in shares)	4,264,068
Weighted-Average Exercise Price
Beginning balance (in dollars per share)	$ 3.83
Granted (in dollars per share)	38.80
Exercised (in dollars per share)	3.53
Forfeited and canceled (in dollars per share)	4.42
Ending balance (in dollars per share)	16.29	$ 3.83
Vested and exercisable (in dollars per share)	4.02
Vested and expected to vest (in dollars per share)	$ 16.29
Additional Disclosures
Weighted-Average Remaining Contractual Term (Years)	6 years 4 months 13 days	5 years 9 months 18 days
Weighted-Average Remaining Contractual Term (Years), vested and exercisable (in years)	4 years 9 months 18 days
Weighted-Average Remaining Contractual Term (Years), vested and expected to vest	6 years 4 months 13 days
Aggregate Intrinsic Value (in thousands)	$ 76,025	$ 149,046
Aggregate Intrinsic Value (in thousands), vested and exercisable	76,626
Aggregate Intrinsic Value (in thousands), vested and expected to vest	$ 76,025