Convertible Preferred Stock, Stockholders’ Equity (Deficit) and Equity Incentive Plan - Schedule of Assumptions for Employee Options at Grant Dates (Details) - Stock options |
12 Months Ended | ||
|---|---|---|---|
Jan. 31, 2020 |
Jan. 31, 2019 |
Jan. 31, 2018 |
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Expected volatility, minimum | 49.90% | 44.60% | 47.70% |
| Expected volatility, maximum | 53.20% | 48.20% | 52.00% |
| Risk-free interest rate, minimum | 1.60% | 2.60% | 1.80% |
| Risk-free interest rate, maximum | 2.50% | 3.10% | 2.30% |
| Expected dividend yield | 0.00% | 0.00% | 0.00% |
| Minimum | |||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Expected term (years) | 5 years | 5 years | 5 years 7 months 6 days |
| Maximum | |||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Expected term (years) | 6 years 1 month 6 days | 6 years 2 months 12 days | 6 years 8 months 12 days |