Balance Sheet Components - Summary of Property and Equipment (Details) - USD ($) $ in Thousands	Apr. 30, 2020	Jan. 31, 2020
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	$ 84,447	$ 79,527
Less accumulated depreciation and amortization	(48,173)	(44,648)
Property and equipment, net	36,274	34,879
Computer equipment and software
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	60,052	56,758
Furniture, fixtures and equipment
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	1,066	1,028
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	6,570	6,941
Equipment acquired under capital leases
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	11,543	11,687
Construction-in-progress
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	$ 5,216	$ 3,113