CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Oct. 31, 2020	Oct. 31, 2019
Cash flows from operating activities:
Net loss	$ (340,167)	$ (265,281)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	6,611	2,257
Non-cash operating lease costs	24,840	19,734
Amortization of deferred commissions	21,233	11,408
Stock-based compensation, net of amounts capitalized	157,790	57,425
Net amortization (accretion) of premiums (discounts) on investments	1,117	(5,149)
Other	4,073	1,276
Changes in operating assets and liabilities, net of effect of acquisitions:
Accounts receivable	9,221	(38,193)
Deferred commissions	(27,261)	(35,004)
Prepaid expenses and other assets	(29,480)	(8,856)
Accounts payable	(3,806)	10,566
Accrued expenses and other liabilities	22,477	14,368
Operating lease liabilities	(23,418)	(6,052)
Deferred revenue	111,739	107,735
Net cash used in operating activities	(65,031)	(133,766)
Cash flows from investing activities:
Purchases of property and equipment	(24,018)	(14,504)
Capitalized internal-use software development costs	(4,014)	(2,940)
Cash paid for acquisitions, net of cash acquired	(6,035)	(6,314)
Purchases of intangible assets	(6,184)	0
Purchases of investments	(1,235,020)	(517,479)
Sales of investments	28,705	3,396
Maturities and redemptions of investments	371,528	691,986
Net cash (used in) provided by investing activities	(875,038)	154,145
Cash flows from financing activities:
Proceeds from issuance of redeemable convertible preferred stock, net of issuance costs	478,573	24,121
Proceeds from initial public offering and private placements, net of underwriting discounts	4,242,284	0
Proceeds from early exercised stock options	159	5,942
Proceeds from exercise of stock options	31,100	21,139
Proceeds from repayments of a nonrecourse promissory note	2,090	0
Repurchases of early exercised stock options and restricted common stock	(30)	(391)
Payments of deferred purchase consideration for acquisitions	(1,164)	0
Net cash provided by financing activities	4,753,012	50,811
Net increase in cash, cash equivalents, and restricted cash	3,812,943	71,190
Cash, cash equivalents, and restricted cash—Beginning of period	141,976	122,570
Cash, cash equivalents, and restricted cash—End of period	3,954,919	193,760
Supplemental disclosures of cash flow information:
Cash paid for income taxes	625	1,025
Supplemental disclosures of non-cash investing and financing activities:
Property and equipment included in accounts payable and accrued expenses	2,803	1,767
Vesting of early exercised stock options and restricted common stock	3,251	5,474
Deferred purchase consideration for acquisitions	1,065	1,164
Equity consideration in connection with an acquisition	0	4,749
Reconciliation of cash, cash equivalents and restricted cash:
Total cash, cash equivalents and restricted cash	$ 3,954,919	$ 193,760