Property and Equipment - Summary of Property and Equipment (Details) - USD ($) $ in Thousands	Apr. 30, 2022	Apr. 30, 2021	Jul. 31, 2020
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 12,711	$ 10,046
Less: Accumulated depreciation and amortization	(5,577)	(3,956)
Property and equipment, net	$ 7,134	$ 6,090
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Property and equipment, net	Property and equipment, net
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	1,667	1,461
Laboratory equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	8,618	6,640
Capitalized software development costs
Property, Plant and Equipment [Line Items]
Total property and equipment	1,888	484	$ 484
Assets in progress
Property, Plant and Equipment [Line Items]
Total property and equipment	181	1,211
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 111	$ 4