Net Loss Per Share Attributable to Common Stockholders - Schedule of Anti-dilutive Outstanding Shares or Equivalents (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive outstanding shares or equivalents	10,546,346	21,553,187	10,546,346	21,553,187
Options To Purchase Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive outstanding shares or equivalents	4,984,240	311,715	4,984,240	311,715
Common Stock Subject To Vesting Or Repurchase
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive outstanding shares or equivalents	5,533,222	6,221,527	5,533,222	6,221,527
Employee Stock Purchase Plan shares
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive outstanding shares or equivalents	28,884		28,884
Redeemable Convertible Preferred Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive outstanding shares or equivalents		15,019,945		15,019,945