Balance Sheet Details - Accrued and Other Current Liabilities (Details) - USD ($) $ in Thousands		Apr. 30, 2021	Apr. 30, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Liability for common stock exercised prior to vesting		$ 5,331	$ 2,243
Accrued general expenses		3,588	1,466
Operating lease liabilities, current		3,894	3,533
Other		5,505	1,841
Accrued and other current liabilities	[1]	$ 18,318	$ 9,083

[1] Including amounts from a related party of $3,413 and nil as of April 30, 2021 and 2020, respectively.