Income Taxes - Deferred Tax Assets (Details) - USD ($) $ in Thousands	Jan. 31, 2022	Jan. 31, 2021
Deferred tax assets:
Net operating loss carryforwards	$ 174,646	$ 70,735
Research and development expenses	36,989	11,479
Accruals and reserves	18,708	12,986
Operating lease liabilities	11,158	5,416
Stock-based compensation	7,936	140
Other	2,012	532
Gross deferred tax assets	251,449	101,288
Valuation allowance	(218,981)	(86,032)
Total deferred tax assets	32,468	15,256
Deferred tax liabilities:
Acquired intangibles, property and equipment	(6,235)	(1,217)
Deferred contract acquisition costs	(16,722)	(9,697)
Operating lease right-of-use assets	(9,422)	(4,342)
Total deferred tax liabilities	(32,379)	(15,256)
Net deferred tax assets	$ 89	$ 0