CONSOLIDATED STATEMENTS OF CASH FLOW - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2022	Jan. 31, 2021	Jan. 31, 2020
Cash flows from operating activities:
Net income	$ 1,375,639	$ 672,316	$ 25,305
Adjustments to reconcile net income to net cash provided by operating activities:
Stock-based compensation expense	477,287	275,818	73,109
Increase (decrease) of valuation allowance	(327,957)	0	0
Amortization of deferred contract acquisition costs	177,283	104,306	37,101
Gains on strategic investments, net	(43,761)	(2,538)	0
Depreciation and amortization	48,188	28,857	16,449
Provision for accounts receivable allowances	36,747	32,007	6,370
Non-cash operating lease cost	18,387	10,887	6,885
Charitable donation of common stock	0	23,312	0
Amortization on marketable securities	25,316	5,433	(2,041)
Other	4,591	927	973
Changes in operating assets and liabilities:
Accounts receivable	(159,183)	(219,039)	(64,715)
Prepaid expenses and other assets	(155,934)	(68,521)	(24,805)
Deferred contract acquisition costs	(247,371)	(307,068)	(72,714)
Accounts payable	(2,218)	3,481	(2,030)
Accrued expenses and other liabilities	101,369	251,654	51,179
Deferred revenue	293,887	665,724	106,286
Operating lease liabilities, net	(17,004)	(6,379)	(5,460)
Net cash provided by operating activities	1,605,266	1,471,177	151,892
Cash flows from investing activities:
Purchases of marketable securities	(4,434,749)	(2,056,470)	(800,228)
Maturities of marketable securities	1,733,043	580,795	343,554
Sales of marketable securities	296,867	36,897	0
Purchases of property and equipment	(132,590)	(79,972)	(38,084)
Purchases of strategic investments	(305,149)	(13,000)	(3,000)
Cash paid for acquisition, net of cash acquired	(3,501)	(26,486)	0
Purchases of intangible assets	(13,018)	(5,843)	(141)
Other	0	1,659	(1,569)
Net cash used in investing activities	(2,859,097)	(1,562,420)	(499,468)
Cash flows from financing activities:
Proceeds from issuance of common stock for employee stock purchase plan	59,331	38,433	15,482
Proceeds from exercise of stock options, net of repurchases	14,404	28,550	9,169
Proceeds from employee equity transactions (remitted) to be remitted to employees and tax authorities, net	(40,004)	4,088	48,547
Proceeds from follow-on public offering, net of underwriting discounts and commissions and other offering costs	0	1,979,206	0
Proceeds from initial public offering and private placement, net of underwriting discounts and commissions and other offering costs	0	0	542,492
Other	337	0	0
Net cash provided by financing activities	34,068	2,050,277	615,690
Net (decrease) increase in cash, cash equivalents, and restricted cash	(1,219,763)	1,959,034	268,114
Cash, cash equivalents, and restricted cash—beginning of year	2,293,116	334,082	65,968
Cash, cash equivalents, and restricted cash—end of year	1,073,353	2,293,116	334,082
Supplemental disclosures of cash flow information
Cash paid for income taxes, net	38,979	3,181	1,070
Supplemental disclosures of non-cash investing and financing information
Purchase of equipment during the period included in accounts payable and accrued expenses	13,728	34,514	1,422
Vesting of early exercised stock options and restricted stock awards	407	558	725
Reconciliation of cash, cash equivalents, and restricted cash within the consolidated balance sheets to the amounts shown in the consolidated statements of cash flows above:
Cash and cash equivalents	1,062,820	2,240,303	283,134
Restricted cash, current included in prepaid expenses and other current assets	10,236	50,575	48,647
Restricted cash, noncurrent included in other assets, noncurrent	297	2,238	2,301
Total cash, cash equivalents, and restricted cash	1,073,353	2,293,116	334,082
Class B Common Stock
Cash flows from operating activities:
Net income	270,271	239,348	19,855
Supplemental disclosures of non-cash investing and financing information
Conversion of convertible preferred stock to Class B common stock upon initial public offering	0	0	159,552
Class A Common Stock
Cash flows from operating activities:
Net income	1,105,368	432,968	5,450
Supplemental disclosures of non-cash investing and financing information
Conversion of debt to Class A common stock	$ 0	$ 0	$ 15,344