Property and Equipment - Summary of Property and Equipment (Details) - USD ($) $ in Thousands	Jan. 31, 2022	Apr. 30, 2021	Jul. 31, 2020
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 11,999	$ 10,046
Less: Accumulated depreciation and amortization	(5,008)	(3,956)
Property and equipment, net	6,991	6,090
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Total property and equipment	246	246
Computer equipment and software
Property, Plant and Equipment [Line Items]
Total property and equipment	1,595	1,461
Capitalized software development costs
Property, Plant and Equipment [Line Items]
Total property and equipment	1,888	484	$ 484
Laboratory equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	8,090	6,640
Assets in progress
Property, Plant and Equipment [Line Items]
Total property and equipment	68	1,211
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 112	$ 4