Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Apr. 30, 2024	Apr. 30, 2023
Deferred tax assets
Accrued payroll	$ 5,542	$ 3,971
Other accruals & reserves	5,933	5,815
Operating lease liability	13,433	8,868
Deferred revenue	1,643	2,221
Net operating losses	141,157	116,111
R&D tax credit	15,001	10,302
Stock based compensation	13,263	10,595
Capitalized R&D expenditure	72,140	30,696
Other	626	457
Gross deferred tax assets	268,738	189,036
Valuation allowance	(252,682)	(180,571)
Total deferred tax assets	16,056	8,465
Deferred tax liabilities
Prepaid expenses	(1,986)	(1,956)
Depreciation	(9,808)	(2,580)
Operating lease right-of-use assets	(4,262)	(3,929)
Total deferred tax liabilities	(16,056)	(8,465)
Net deferred tax assets (liabilities)	$ 0	$ 0