CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOW - USD ($) $ in Thousands	9 Months Ended
	Oct. 31, 2020	Oct. 31, 2019
Cash flows from operating activities:
Net income	$ 411,706	$ 9,966
Adjustments to reconcile net income to net cash provided by operating activities:
Stock-based compensation expense	179,557	46,532
Amortization of deferred contract acquisition costs	71,281	25,939
Charitable donation of common stock	23,312	0
Provision for accounts receivable allowances	20,218	3,976
Depreciation and amortization	19,401	11,589
Non-cash operating lease cost	7,182	4,840
Remeasurement gain on equity investment	(2,538)	0
Other	3,717	(1,577)
Changes in operating assets and liabilities:
Accounts receivable	(190,117)	(36,886)
Prepaid expenses and other assets	(48,258)	(22,439)
Deferred contract acquisition costs	(266,294)	(50,824)
Accounts payable	8,773	(1,118)
Accrued expenses and other liabilities	203,919	53,485
Deferred revenue	633,600	76,579
Operating lease liabilities, net	(3,678)	(4,724)
Net cash provided by operating activities	1,071,781	115,338
Cash flows from investing activities:
Purchases of marketable securities	(1,016,109)	(629,107)
Maturities of marketable securities	406,607	164,140
Sales of marketable securities	36,897	0
Purchases of property and equipment	(58,517)	(28,132)
Sales of property and equipment	297	0
Cash paid for acquisition, net of cash acquired	(26,486)	0
Purchase of equity investment	(8,000)	(3,000)
Purchase of convertible promissory note	(5,000)	0
Purchase of intangible assets	(4,385)	0
Collections of employee loans	1,319	0
Net cash used in investing activities	(673,377)	(496,099)
Cash flows from financing activities:
Proceeds from employee equity transactions to be remitted to employees and tax authorities, net	251,641	48,547
Proceeds from issuance of common stock for employee stock purchase plan	20,760	0
Proceeds from exercise of stock options, net of repurchases	23,841	5,584
Proceeds from initial public offering and private placement, net of underwriting discounts and commissions and other offering costs	0	542,492
Net cash provided by financing activities	296,242	596,623
Net increase in cash, cash equivalents, and restricted cash	694,646	215,862
Cash, cash equivalents, and restricted cash – beginning of period	334,082	65,968
Cash, cash equivalents, and restricted cash – end of period	1,028,728	281,830
Reconciliation of cash, cash equivalents, and restricted cash within the condensed consolidated balance sheets to the amounts shown in the condensed consolidated statements of cash flows above:
Cash and cash equivalents	730,506	230,874
Total cash, cash equivalents, and restricted cash	$ 1,028,728	$ 281,830