Net Loss Per Share Attributable to Common Stockholders - Antidilutive (Details) - shares shares in Thousands	12 Months Ended
	Jan. 31, 2022	Jan. 31, 2021	Jan. 31, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential common shares excluded from diluted net loss per share (in shares)	12,664	16,515	23,194
Shares of common stock subject to repurchase from outstanding stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential common shares excluded from diluted net loss per share (in shares)	198	548	984
RSUs and PSUs subject to future vesting
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential common shares excluded from diluted net loss per share (in shares)	7,886	8,449	6,063
Shares of common stock issuable from stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential common shares excluded from diluted net loss per share (in shares)	3,938	6,646	14,689
Share purchase rights under the employee stock purchase plan
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential common shares excluded from diluted net loss per share (in shares)	642	872	1,458