v3.20.4
Convertible Preferred Stock, Stockholders’ Equity (Deficit) and Equity Incentive Plan (Tables)
 12 Months Ended
Jan. 31, 2021
Equity [Abstract]  
Schedule of Stock by Class Reserved for Future Issuance
We have the following shares of Class A common stock reserved for future issuance:
 
As of January 31,
 20212020
Stock options outstanding9,239,504 16,833,009 
RSUs outstanding4,510,730 1,964,668 
ESPP purchase rights outstanding 724,883 1,323,662 
Remaining shares available for future issuance under the 2011 and 2019 plan44,584,783 33,604,587 
Remaining shares available for future issuance under the ESPP9,648,574 7,186,070 
Total shares of Class A common stock reserved68,708,474 60,911,996 
Summary of Stock Option Activity Under Equity Incentive Plan
A summary of stock option activity under our equity incentive plan and related information is as follows:
Stock Options
 Outstanding
Stock
Options		Weighted-
Average
Exercise
Price		Weighted-
Average
Remaining
Contractual
Life (Years)		Aggregate
Intrinsic
Value
 (in thousands, except share, life and per share data)
Balance as of January 31, 202016,833,009 $5.73 7.6$1,191,881 
Granted— $— 
Exercised(7,378,477)$3.87 $1,786,657 
Canceled/forfeited/expired(215,028)$8.05 
Balance as of January 31, 20219,239,504 $7.17 7.0$3,371,457 
Vested and exercisable as of January 31, 20214,641,908 $3.98 6.6$1,708,663 
There were no options granted for the fiscal year ended January 31, 2021.
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions
The Black-Scholes assumptions used to value the employee options at the grant dates are as follows:

Year ended January 31,
20202019
Expected term (years)
5.0 - 6.1
5.0 - 6.2
Expected volatility
49.9% - 53.2%
44.6% - 48.2%
Risk-free interest rate
1.6% - 2.5%
2.6% - 3.1%
Expected dividend yield——
Summary of Restricted Stock Units (RSUs) Activity Under Equity Incentive Plan
A summary of RSU activity under our equity incentive plan and related information is as follows:
RSUs
Unvested
RSUs		Weighted-Average
Grant Date Fair Value Per Share
Unvested as of January 31, 20201,964,668 $79.11 
Granted3,351,979 $241.32 
Vested(625,163)$86.29 
Canceled/forfeited(180,754)$181.18 
Unvested as of January 31, 20214,510,730 $194.57 
Summary of Assumptions for Estimating Fair Value of ESPP Purchase Rights
We estimated the fair value of ESPP purchase rights using a Black-Scholes option-pricing model with the following assumptions:
Year ended January 31,
20212020
Expected term (years)
0.5 - 2.1
0.5 - 2.1
Expected volatility
40.3% - 75.0%
40.3% - 56.2%
Risk-free interest rate
0.1% - 2.5%
1.5% - 2.5%
Expected dividend yield——
Summary of Stock-based Compensation Expense by Line Item
The stock-based compensation expense by line item in the accompanying consolidated statements of operations is summarized as follows:
Year Ended January 31,
202120202019
(in thousands)
Cost of revenue$34,960 $7,860 $1,119 
Research and development50,161 11,645 1,369 
Sales and marketing146,377 41,465 3,540 
General and administrative44,320 12,139 2,913 
Total stock-based compensation expense$275,818 $73,109 $8,941