Consolidated Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2019
Income Statement And Statement Of Comprehensive Income [Abstract]
Revenue	$ 213,556	$ 166,351	$ 117,823
Cost of revenue	30,686	24,579	17,255
Gross profit	182,870	141,772	100,568
Operating expenses:
Research and development	64,566	49,011	38,858
Sales and marketing	122,155	97,350	64,060
General and administrative	62,431	50,970	39,971
Total operating expenses	249,152	197,331	142,889
Loss from operations	(66,282)	(55,559)	(42,321)
Interest income	4,232	5,692	1,249
Interest expense	(9,965)	0	0
Other (expense) income, net	(794)	203	1,032
Loss before benefit from (provision for) income taxes	(72,809)	(49,664)	(40,040)
Benefit from (provision for) income taxes	3,906	(675)	(701)
Net loss	(68,903)	(50,339)	(40,741)
Other comprehensive gain:
Unrealized gain on investments	206	137	0
Total comprehensive loss	$ (68,697)	$ (50,202)	$ (40,741)
Net loss per share, basic and diluted (in dollars per share)	$ (0.87)	$ (0.77)	$ (1.90)
Weighted average shares used in calculating net loss per share, basic and diluted (in shares)	79,614	65,544	21,410