Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Jan. 31, 2022	Jan. 31, 2021
Cash flows from operating activities:
Net loss	$ (16,821)	$ (24,425)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	3,262	1,546
Share-based compensation	3,820	1,652
Warrant contra revenue	407	0
Write-downs for excess and obsolete inventory	1,256	1,028
Changes in operating assets and liabilities:
Accounts receivable	(8,049)	5,167
Inventories	(20,274)	(4,348)
Prepaid and other current assets	(585)	(807)
Other non-current assets	(2,164)	(434)
Accounts payable	3,245	911
Accrued expenses, compensation and other liabilities	5,890	(7,932)
Deferred revenue, net of contract assets	(3,179)	(3,207)
Net cash used in operating activities	(33,192)	(30,849)
Cash flows from investing activities:
Purchases of property and equipment	(7,932)	(6,532)
Net cash used in investing activities	(7,932)	(6,532)
Cash flows from financing activities:
Proceeds from issuance of ordinary shares upon initial public offering, net of underwriter discounts	171,889	0
Payments for deferred offering costs	(3,056)	0
Proceeds from employee stock options exercises	1,936	1,146
Proceeds from issuance of convertible preferred shares, net of issuance costs	7,245	99,436
Payments for repurchase of ordinary shares	0	(22,908)
Net cash provided by financing activities	178,014	77,674
Effect of exchange rate changes on cash	(118)	405
Net increase in cash and cash equivalents	136,772	40,698
Cash and cash equivalents at beginning of the period	103,757	73,908
Cash and cash equivalents at end of the period	240,529	114,606
Supplemental cash flow information:
Property and equipment received and accrued in accounts payable	200	134
Conversion of convertible preferred share into ordinary share upon initial public offering	205,210	0
Deferred offering costs included in accounts payable and accrued expenses	$ 2,239	$ 0