Condensed Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total		Class A common stock	Class B common stock	Common Stock Class A common stock	Common Stock Class B common stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income	Accumulated Deficit
Beginning balance (in shares) at Jan. 31, 2019					77,119	32,575
Beginning balance at Jan. 31, 2019	$ 181,814				$ 8	$ 3	$ 488,776	$ 481	$ (307,454)
Conversion of Class B common stock to Class A common stock (in shares)					7,909
Conversion of Class B common stock to Class A common stock (in shares)						(7,909)
Conversion of Class B common stock to Class A common stock	0
Issuance of common stock upon exercise of stock options, net of repurchases (in shares)					(7)
Issuance of common stock upon exercise of stock options, net of repurchases (in shares)						1,247
Issuance of common stock upon exercise of stock options, net of repurchases	4,846						4,846
Lapse of restrictions on common stock related to early exercise of stock options	205						205
RSU releases (in shares)					76	51
RSU releases	0
Deferred offering costs	38						38
Stock-based compensation	7,959						7,959
Other comprehensive loss	(51)							(51)
Net loss	(20,592)	[1]							(20,592)
Ending balance (in shares) at Apr. 30, 2019					85,097	25,964
Ending balance at Apr. 30, 2019	174,219				$ 8	$ 3	501,824	430	(328,046)
Beginning balance (in shares) at Jan. 31, 2020					97,134	17,348
Beginning balance at Jan. 31, 2020	164,659				$ 10	$ 2	555,307	188	(390,848)
Conversion of Class B common stock to Class A common stock (in shares)					2,186
Conversion of Class B common stock to Class A common stock (in shares)						(2,186)
Conversion of Class B common stock to Class A common stock	$ 0
Issuance of common stock upon exercise of stock options, net of repurchases (in shares)					(2)
Issuance of common stock upon exercise of stock options, net of repurchases (in shares)	856					856
Issuance of common stock upon exercise of stock options, net of repurchases	$ 4,009						4,009
Lapse of restrictions on common stock related to early exercise of stock options	39						39
RSU releases (in shares)					337	40
RSU releases	0
Stock-based compensation	10,884						10,884
Other comprehensive loss	(270)							(270)
Net loss	(17,488)								(17,488)
Ending balance (in shares) at Apr. 30, 2020			99,700	16,100	99,655	16,058
Ending balance at Apr. 30, 2020	$ 161,833				$ 10	$ 2	$ 570,239	$ (82)	$ (408,336)

[1] Effective February 1, 2019, the Company adopted Topic 842 using the modified retrospective approach. See Note 2. Summary of Significant Accounting Policies and Recent Accounting Pronouncements.