CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Apr. 30, 2021	Apr. 30, 2020
CURRENT ASSETS:
Cash and cash equivalents	$ 169,915	$ 36,262
Accounts receivable	18,842	8,606
Contract assets	6,112	3,300
Inventory	11,871	10,883
Prepaid expenses	1,064	712
Total current assets	207,804	59,763
Property and equipment, net	37,455	27,105
Operating lease right-of-use assets	18,691	20,100
Restricted cash	350	350
Other assets	1,210	302
TOTAL ASSETS	265,510	107,620
CURRENT LIABILITIES:
Accounts payable	9,257	5,926
Accrued payroll and related costs	8,794	3,019
Contract liabilities	50,769	29,120
Current portion of operating lease liabilities	1,355	1,228
Note payable	0	4,379
Other current liabilities	761	808
Total current liabilities	70,936	44,480
Convertible senior notes, net	96,949	0
Operating lease liabilities, less current portion	19,889	21,244
Total liabilities	187,774	65,724
STOCKHOLDERS' EQUITY:
Preferred stock, $0.001 par value; 5,000 shares authorized; no shares and 1,648 shares issued and outstanding at respective dates	0	2
Common stock, $0.001 par value; 150,000 shares authorized; 61,069 and 56,483 shares issued and outstanding at respective dates	61	56
Additional paid-in-capital	637,534	612,909
Accumulated deficit	(559,859)	(571,071)
Total stockholders' equity	77,736	41,896
Total liabilities and stockholders' equity	$ 265,510	$ 107,620