Convertible Preferred Stock, Stockholders’ Equity (Deficit) and Equity Incentive Plan - Schedule of Stock by Class Reserved for Future Issuance (Details) - shares	Jan. 31, 2021	Jan. 31, 2020
Class of Stock [Line Items]
Number of shares available for future issuance (in shares)	68,708,474	60,911,996
Stock options
Class of Stock [Line Items]
Number of shares available for future issuance (in shares)	9,239,504	16,833,009
RSUs
Class of Stock [Line Items]
Number of shares available for future issuance (in shares)	4,510,730	1,964,668
ESPP
Class of Stock [Line Items]
Number of shares available for future issuance (in shares)	724,883	1,323,662
2011 and 2019 Plan
Class of Stock [Line Items]
Number of shares available for future issuance (in shares)	44,584,783	33,604,587
2019 Employee Stock Purchase Plan | ESPP
Class of Stock [Line Items]
Number of shares available for future issuance (in shares)	9,648,574	7,186,070