Net Loss per Share - Schedule of Potentially Dilutive Securities (Details) - shares shares in Thousands	9 Months Ended	12 Months Ended
	Oct. 31, 2021	Jan. 31, 2021
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities (in shares)	23,703	97,177
Shares subject to outstanding common stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities (in shares)	19,722	16,043
Unvested early exercised stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities (in shares)	908	1,510
Convertible preferred stock (on an if-converted basis)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities (in shares)	0	79,551
RSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities (in shares)	3,000	0
Warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities (in shares)	73	73