MongoDB (MDB) 10-Q 10 Dec 19 2020 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Oct. 31, 2019	Dec. 05, 2019
Cover page.
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Oct. 31, 2019
Document Transition Report	false
Entity File Number	001-38240
Entity Registrant Name	MONGODB, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	26-1463205
Entity Address, Address Line One	1633 Broadway
Entity Address, Address Line Two	38th Floor
Entity Address, City or Town	New York
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10019
City Area Code	646
Local Phone Number	727-4092
Title of 12(b) Security	Class A Common Stock, par value $0.001 per share
Trading Symbol	MDB
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Central Index Key	0001441816
Current Fiscal Year End Date	--01-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q3
Amendment Flag	false
Class A Common Stock
Entity Common Stock, Shares Outstanding		47,744,886
Class B Common Stock
Entity Common Stock, Shares Outstanding		8,998,700

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Oct. 31, 2019	Jan. 31, 2019
Current assets:
Cash and cash equivalents	$ 151,307	$ 147,831
Short-term investments	274,560	318,139
Accounts receivable, net of allowance for doubtful accounts of $2,213 and $1,539 as of October 31, 2019 and January 31, 2019, respectively	67,506	72,808
Deferred commissions	19,717	15,878
Prepaid expenses and other current assets	12,531	11,580
Total current assets	525,621	566,236
Property and equipment, net	59,418	73,664
Operating lease right-of-use assets	12,151	0
Goodwill	55,484	41,878
Acquired intangible assets, net	36,982	15,894
Deferred tax assets	2,206	1,193
Other assets	43,123	34,611
Total assets	734,985	733,476
Current liabilities:
Accounts payable	2,124	2,153
Accrued compensation and benefits	31,335	25,982
Operating lease liabilities (current)	4,180	0
Other accrued liabilities	29,094	14,169
Deferred revenue	137,789	122,333
Total current liabilities	204,522	164,637
Deferred rent, non-current	0	2,567
Deferred tax liability, non-current	114	106
Operating lease liabilities, non-current	9,044	0
Deferred revenue, non-current	14,601	15,343
Convertible senior notes, net	226,690	216,858
Other liabilities, non-current	61,179	69,399
Total liabilities	516,150	468,910
Commitments and contingencies (Note 8)
Stockholders’ equity:
Additional paid-in capital	825,577	754,612
Treasury stock, 99,371 shares (repurchased at an average of $13.27 per share) as of October 31, 2019 and January 31, 2019	(1,319)	(1,319)
Accumulated other comprehensive income (loss)	189	(174)
Accumulated deficit	(605,669)	(488,607)
Total stockholders’ equity	218,835	264,566
Total liabilities and stockholders’ equity	734,985	733,476
Class A Common Stock
Stockholders’ equity:
Common stock	48	36
Class B Common Stock
Stockholders’ equity:
Common stock	$ 9	$ 18

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parentheticals) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Oct. 31, 2019	Jan. 31, 2019
Current assets:
Allowance for doubtful accounts	$ 2,213	$ 1,539
Stockholders’ equity:
Treasury stock (in shares)	99,371	99,371
Average repurchase price of treasury stock shares (in dollars per share)	$ 13.27	$ 13.27
Class A Common Stock
Stockholders’ equity:
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock authorized (in shares)	1,000,000,000	1,000,000,000
Common stock issued (in shares)	47,583,572	36,286,573
Common stock outstanding (in shares)	47,583,572	36,286,573
Class B Common Stock
Stockholders’ equity:
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock authorized (in shares)	100,000,000	100,000,000
Common stock issued (in shares)	9,194,461	18,134,608
Common stock outstanding (in shares)	9,095,090	18,035,237

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2019	Oct. 31, 2018
Revenue:
Total revenue	$ 109,441	$ 71,782	$ 298,197	$ 181,532
Cost of revenue:
Total cost of revenue	32,191	17,758	90,565	48,001
Gross profit	77,250	54,024	207,632	133,531
Operating expenses:
Sales and marketing	57,015	36,080	156,659	105,814
Research and development	39,387	23,179	107,395	63,254
General and administrative	19,562	14,986	50,541	38,467
Total operating expenses	115,964	74,245	314,595	207,535
Loss from operations	(38,714)	(20,221)	(106,963)	(74,004)
Other income (expense):
Interest income	1,986	2,459	6,520	4,936
Interest expense	(4,813)	(4,358)	(14,442)	(5,652)
Other expense, net	(283)	(400)	(994)	(1,424)
Loss before provision for income taxes	(41,824)	(22,520)	(115,879)	(76,144)
Provision (benefit) for income taxes	559	(33)	(2,920)	680
Net loss	$ (42,383)	$ (22,487)	$ (112,959)	$ (76,824)
Net loss per share, basic and diluted (in dollars per share)	$ (0.75)	$ (0.43)	$ (2.03)	$ (1.49)
Weighted-average shares used to compute net loss per share, basic and diluted (in shares)	56,411,779	52,702,526	55,600,484	51,431,021
Subscription
Revenue:
Total revenue	$ 103,827	$ 66,604	$ 281,977	$ 167,759
Cost of revenue:
Total cost of revenue	26,497	13,248	73,465	35,434
Services
Revenue:
Total revenue	5,614	5,178	16,220	13,773
Cost of revenue:
Total cost of revenue	$ 5,694	$ 4,510	$ 17,100	$ 12,567

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2019	Oct. 31, 2018
Statement of Comprehensive Income [Abstract]
Net loss	$ (42,383)	$ (22,487)	$ (112,959)	$ (76,824)
Other comprehensive income (loss), net of tax:
Unrealized gain (loss) on available-for-sale securities	219	9	298	(43)
Foreign currency translation adjustment	302	(49)	65	(178)
Other comprehensive income (loss)	521	(40)	363	(221)
Total comprehensive loss	$ (41,862)	$ (22,527)	$ (112,596)	$ (77,045)

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY - USD ($) $ in Thousands	Total	Class A and Class B Common Stock	Additional Paid-In Capital	Treasury Stock	Accumulated Other Comprehensive Loss	Accumulated Deficit
Beginning balance (in shares) at Jan. 31, 2018		50,575,571
Beginning balance at Jan. 31, 2018	$ 247,657	$ 51	$ 638,680	$ (1,319)	$ (159)	$ (389,596)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock option exercises (in shares)		40,723
Stock option exercises	183		183
Repurchase of early exercised options (in shares)		(19,395)
Vesting of early exercised stock options	533		533
Vesting of restricted stock units (in shares)		125
Stock-based compensation	7,577		7,577
Unrealized gain on available-for-sale securities	(82)				(82)
Foreign currency translation adjustment	(33)				(33)
Net loss	(26,555)					(26,555)
Ending balance (in shares) at Apr. 30, 2018		50,597,024
Ending balance at Apr. 30, 2018	229,280	$ 51	646,973	(1,319)	(274)	(416,151)
Beginning balance (in shares) at Jan. 31, 2018		50,575,571
Beginning balance at Jan. 31, 2018	247,657	$ 51	638,680	(1,319)	(159)	(389,596)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Unrealized gain on available-for-sale securities	(43)
Foreign currency translation adjustment	(178)
Net loss	(76,824)
Ending balance (in shares) at Oct. 31, 2018		53,496,249
Ending balance at Oct. 31, 2018	266,315	$ 53	734,381	(1,319)	(380)	(466,420)
Beginning balance (in shares) at Apr. 30, 2018		50,597,024
Beginning balance at Apr. 30, 2018	229,280	$ 51	646,973	(1,319)	(274)	(416,151)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock option exercises (in shares)		1,150,864
Stock option exercises	7,895	$ 1	7,894
Repurchase of early exercised options (in shares)		(14,000)
Vesting of early exercised stock options	302		302
Vesting of restricted stock units (in shares)		75,478
Stock-based compensation	9,009		9,009
Issuance of common stock under the Employee Stock Purchase Plan (in shares)		275,874
Issuance of common stock under the Employee Stock Purchase Plan	5,626		5,626
Equity component of convertible senior notes	81,683		81,683
Purchase of capped calls	(37,086)		(37,086)
Unrealized gain on available-for-sale securities	30				30
Foreign currency translation adjustment	(96)				(96)
Net loss	(27,782)					(27,782)
Ending balance (in shares) at Jul. 31, 2018		52,085,240
Ending balance at Jul. 31, 2018	268,861	$ 52	714,401	(1,319)	(340)	(443,933)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock option exercises (in shares)		1,348,725
Stock option exercises	9,507	$ 1	9,506
Repurchase of early exercised options (in shares)		(2,168)
Vesting of early exercised stock options	210		210
Vesting of restricted stock units (in shares)		63,209
Stock-based compensation	10,264		10,264
Issuance of common stock under the Employee Stock Purchase Plan (in shares)		1,243
Issuance of common stock under the Employee Stock Purchase Plan	0		0
Unrealized gain on available-for-sale securities	9				9
Foreign currency translation adjustment	(49)				(49)
Net loss	(22,487)					(22,487)
Ending balance (in shares) at Oct. 31, 2018		53,496,249
Ending balance at Oct. 31, 2018	266,315	$ 53	734,381	(1,319)	(380)	(466,420)
Beginning balance (in shares) at Jan. 31, 2019		54,321,810
Beginning balance at Jan. 31, 2019	264,566	$ 54	754,612	(1,319)	(174)	(488,607)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock option exercises (in shares)		831,901
Stock option exercises	6,438	$ 1	6,437
Repurchase of early exercised options (in shares)		(3,981)
Vesting of early exercised stock options	127		127
Vesting of restricted stock units (in shares)		126,346
Stock-based compensation	14,009		14,009
Unrealized gain on available-for-sale securities	58				58
Foreign currency translation adjustment	13				13
Net loss	(33,240)					(33,240)
Ending balance (in shares) at Apr. 30, 2019		55,276,076
Ending balance at Apr. 30, 2019	247,868	$ 55	775,185	(1,319)	(103)	(525,950)
Beginning balance (in shares) at Jan. 31, 2019		54,321,810
Beginning balance at Jan. 31, 2019	$ 264,566	$ 54	754,612	(1,319)	(174)	(488,607)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock option exercises (in shares)	1,729,833
Unrealized gain on available-for-sale securities	$ 298
Foreign currency translation adjustment	65
Net loss	(112,959)
Ending balance (in shares) at Oct. 31, 2019		56,678,662
Ending balance at Oct. 31, 2019	218,835	$ 57	825,577	(1,319)	189	(605,669)
Beginning balance (in shares) at Apr. 30, 2019		55,276,076
Beginning balance at Apr. 30, 2019	247,868	$ 55	775,185	(1,319)	(103)	(525,950)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock option exercises (in shares)		665,543
Stock option exercises	4,914	$ 1	4,913
Repurchase of early exercised options (in shares)		(209)
Vesting of early exercised stock options	70		70
Vesting of restricted stock units (in shares)		206,587
Stock-based compensation	17,662		17,662
Issuance of common stock under the Employee Stock Purchase Plan (in shares)		90,619
Issuance of common stock under the Employee Stock Purchase Plan	6,394		6,394
Unrealized gain on available-for-sale securities	21				21
Foreign currency translation adjustment	(250)				(250)
Net loss	(37,336)					(37,336)
Ending balance (in shares) at Jul. 31, 2019		56,238,616
Ending balance at Jul. 31, 2019	239,343	$ 56	804,224	(1,319)	(332)	(563,286)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock option exercises (in shares)		232,389
Stock option exercises	1,934	$ 1	1,933
Repurchase of early exercised options (in shares)		(542)
Vesting of early exercised stock options	53		53
Vesting of restricted stock units (in shares)		208,199
Stock-based compensation	19,367		19,367
Unrealized gain on available-for-sale securities	219				219
Foreign currency translation adjustment	302				302
Net loss	(42,383)					(42,383)
Ending balance (in shares) at Oct. 31, 2019		56,678,662
Ending balance at Oct. 31, 2019	$ 218,835	$ 57	$ 825,577	$ (1,319)	$ 189	$ (605,669)

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Oct. 31, 2019	Oct. 31, 2018
Cash flows from operating activities
Net loss	$ (112,959)	$ (76,824)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	9,824	3,334
Stock-based compensation	51,038	26,850
Amortization of debt discount and issuance costs	9,833	4,233
Amortization of finance right-of-use assets	2,982	0
Amortization of operating right-of-use assets	2,055	0
Non-cash interest on finance lease liabilities	1,823	659
Deferred income taxes	(4,541)	(351)
Accretion of discount on short-term investments	(3,619)	(2,567)
Change in operating assets and liabilities:
Accounts receivable	5,123	3,783
Prepaid expenses and other current assets	189	(1,451)
Deferred commissions	(12,205)	(9,585)
Other long-term assets	(148)	(33)
Accounts payable	(152)	(165)
Deferred rent	0	1,258
Accrued liabilities	16,176	7,184
Operating lease liabilities	(1,979)	0
Deferred revenue	14,898	11,166
Other liabilities, non-current	740	0
Net cash used in operating activities	(20,922)	(32,509)
Cash flows from investing activities
Purchases of property and equipment	(2,350)	(3,698)
Acquisition, net of cash acquired	(38,629)	0
Proceeds from maturities of marketable securities	410,000	206,000
Purchases of marketable securities	(363,530)	(369,736)
Net cash provided by (used in) investing activities	5,491	(167,434)
Cash flows from financing activities
Proceeds from exercise of stock options, including early exercised stock options	13,283	17,631
Proceeds from the issuance of common stock under the Employee Stock Purchase Plan	6,394	5,626
Repurchase of early exercised stock options	(35)	(327)
Principal repayments of finance leases	(798)	0
Proceeds from borrowings on convertible senior notes, net of issuance costs	0	291,145
Payment for purchase of capped calls	0	(37,086)
Proceeds from tenant improvement allowance on build-to-suit lease	0	633
Net cash provided by financing activities	18,844	277,622
Effect of exchange rate changes on cash, cash equivalents and restricted cash	62	(101)
Net increase in cash, cash equivalents and restricted cash	3,475	77,578
Cash, cash equivalents and restricted cash, beginning of period	148,347	62,427
Cash, cash equivalents and restricted cash, end of period	151,822	140,005
Noncash investing and financing activities:
Construction in progress related to build-to-suit lease obligations	0	11,683
Reconciliation of cash, cash equivalents and restricted cash within the condensed consolidated balance sheets, end of period, to the amounts shown in the statements of cash flows above
Total cash, cash equivalents and restricted cash	$ 151,822	$ 140,005

Organization and Description of

Organization and Description of Business	9 Months Ended
	Oct. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Description of Business	Organization and Description of Business MongoDB, Inc. (“MongoDB” or the “Company”) was originally incorporated in the state of Delaware in November 2007 under the name 10Gen, Inc. In August 2013, the Company changed its name to MongoDB, Inc. The Company is headquartered in New York City. MongoDB is the leading, modern, general purpose database platform. The Company’s robust platform enables developers to build and modernize applications rapidly and cost-effectively across a broad range of use cases. Organizations can deploy the Company’s platform at scale in the cloud, on-premise, or in a hybrid environment. In addition to selling its software, the Company provides post-contract support, training and consulting services for its offerings. The Company’s fiscal year ends January 31 .

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Oct. 31, 2019
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation The accompanying interim condensed consolidated balance sheet as of October 31, 2019 , the interim condensed consolidated statements of stockholders’ equity for the three and nine months ended October 31, 2019 and 2018 , the interim condensed consolidated statements of operations and of comprehensive loss for the three and nine months ended October 31, 2019 and 2018 and the interim condensed consolidated statements of cash flows for the nine months ended October 31, 2019 and 2018 are unaudited. The interim unaudited condensed consolidated financial statements have been prepared on a basis consistent with the annual consolidated financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary to state fairly the Company’s financial position as of October 31, 2019 , its statements of stockholders’ equity as of October 31, 2019 and 2018 , its results of operations and of comprehensive loss for the three and nine months ended October 31, 2019 and 2018 and its statements of cash flows for the nine months ended October 31, 2019 and 2018 . The financial data and the other financial information disclosed in the notes to these interim condensed consolidated financial statements related to the three and nine -month periods are also unaudited. The results of operations for the three and nine months ended October 31, 2019 are not necessarily indicative of the results to be expected for the fiscal year ending January 31, 2020 or for any other future year or interim period. The interim unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and include the accounts of the Company and its wholly owned subsidiaries. All intercompany transactions and accounts have been eliminated. Certain information and note disclosures normally included in the financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to the applicable rules and regulations of the Securities and Exchange Commission. The condensed balance sheet data as of January 31, 2019 was derived from the Company’s audited financial statements, but does not include all disclosures required by U.S. GAAP. Therefore, these interim unaudited condensed consolidated financial statements and accompanying footnotes should be read in conjunction with the Company’s annual consolidated financial statements and related footnotes included in its Annual Report on Form 10-K for the fiscal year ended January 31, 2019 (the “2019 Form 10-K”). Effective February 1, 2018, the Company adopted Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers (Topic 606) . All amounts and disclosures in this Quarterly Report on Form 10-Q have been updated to comply with the new revenue standard. Use of Estimates The preparation of the interim unaudited condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. Such estimates include, but are not limited to, revenue recognition, allowances for doubtful accounts, stock-based compensation, legal contingencies, fair value of acquired intangible assets and goodwill, useful lives of acquired intangible assets and property and equipment, fair value of property and equipment and accounting for income taxes. The Company bases these estimates on historical and anticipated results, trends and various other assumptions that it believes are reasonable under the circumstances, including assumptions as to future events. Actual results could differ from those estimates. Significant Accounting Policies There have been no changes to the Company’s significant accounting policies as described in the Company’s 2019 Form 10-K other than the adoption of the new accounting guidance related to leases and stock-based compensation, effective February 1, 2019, as discussed in “Recently Adopted Accounting Pronouncements” below. Further disclosures with respect to the Company’s leases are also included in Note 7, Leases . Related Party Transactions All contracts with related parties are executed in ordinary course of business. There were no material related party transactions in the three and nine months ended October 31, 2019 and 2018 . As of October 31, 2019 and January 31, 2019 , there were no material amounts payable to or amounts receivable from related parties. Recently Adopted Accounting Pronouncements Leases. In February 2016, the Financial Accounting Standards Board issued ASU No. 2016-02, codified as Accounting Standards Codification 842 (“ASC 842”), which requires lessees to record the assets and liabilities arising from all leases, with the exception of short-term leases, on the balance sheet. Under ASC 842, lessees will recognize a liability for lease payments and a right-of-use asset. This guidance retains the distinction between finance leases and operating leases and the classification criteria for finance leases remains similar. For finance leases, a lessee will recognize the interest on a lease liability separate from amortization of the right-of-use asset. In addition, repayments of principal will be presented within financing activities, and interest payments will be presented within operating activities in the statement of cash flows. For operating leases, a lessee will recognize a single lease cost on a straight-line basis and classify all cash payments within operating activities in the statement of cash flows. The Company adopted the new lease accounting standard effective February 1, 2019 using the additional transition method described in ASU No. 2018-11, Leases – Targeted Improvements , which was issued in July 2018. Under the additional transition method, the Company recognized the cumulative effect of initially applying the guidance as an adjustment to the operating lease right-of-use assets and operating lease liabilities on its condensed consolidated balance sheet on February 1, 2019 without retrospective application to comparative periods. The adoption of ASC 842 resulted in recognition of right-of-use assets of $53.7 million , which included the impact of existing deferred rents of $2.9 million and lease liabilities of $70.2 million , along with a cumulative impact of $4.1 million on the opening accumulated deficit, as of February 1, 2019. The Company elected the package of practical expedients permitted under the transition guidance within ASC 842, which allowed the Company to carry forward its historical assessments of whether contracts are or contain leases, lease classification and initial direct costs. See Note 7, Leases , for additional details. The Company determines if an arrangement is, or contains, a lease at inception. Operating leases are disclosed separately on the condensed consolidated balance sheets and the finance lease is included in property and equipment, net, other accrued liabilities and other liabilities, non-current. The Company has elected an accounting policy to not recognize short-term leases (one year or less) on the consolidated balance sheet. Operating lease right-of-use assets and operating lease liabilities are recognized based on the present value of the lease payments over the lease term at commencement date. As most of the Company’s leases do not provide an implicit rate, the Company’s incremental borrowing rate is used based on the information available at commencement date in determining the present value of future payments. The operating lease right-of-use asset also includes any lease payments made and excludes lease incentives. Lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Lease expense for minimum lease payments is recognized on a straight-line basis over the lease term. Variable lease payments are expensed as incurred and are not included within the lease liability and right-of-use assets calculation. The Company accounts for lease components and non-lease components as a single lease component. Stock-Based Compensation. In June 2018, the FASB issued ASU No. 2018-07, Compensation - Stock Compensation (Topic 718): Improvements to Non-employee Share-Based Payment Accounting , which expands the scope of Topic 718 to include share-based payment transactions for acquiring goods and services from non-employees, with certain exceptions. The new guidance was effective for the Company for fiscal year beginning February 1, 2019 and the adoption had no material impact on its condensed consolidated financial statements. New Accounting Pronouncements Not Yet Adopted Goodwill Impairment. In January 2017, the FASB issued ASU No. 2017-04— Intangibles—Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment . The new standard simplifies the measurement of goodwill by eliminating step two of the two-step impairment test. Step two measures a goodwill impairment loss by comparing the implied fair value of a reporting unit’s goodwill with the carrying amount of that goodwill. The new guidance requires an entity to compare the fair value of a reporting unit with its carrying amount and recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value. Additionally, an entity should consider income tax effects from any tax-deductible goodwill on the carrying amount of the reporting unit when measuring the goodwill impairment loss, if applicable. The new guidance becomes effective for the Company for the fiscal year beginning February 1, 2020, though early adoption is permitted. The Company does not expect the adoption of the new accounting standard to have a material impact on its condensed consolidated financial statements. Cloud Computing. In August 2018, the FASB issued ASU No. 2018-15, Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract , which aligns the accounting for implementation costs incurred in a hosting arrangement that is a service contract with the accounting for implementation costs incurred to develop or obtain internal-use software under ASC 350-40, in order to determine which costs to capitalize and recognize as an asset and which costs to expense. ASU No. 2018-15 becomes effective for the Company for the fiscal year beginning February 1, 2020, with early adoption permitted, and can be applied either prospectively to implementation costs incurred after the date of adoption or retrospectively to all arrangements. The Company is currently evaluating the impact of the adoption of this standard on its condensed consolidated financial statements. Credit Losses. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments , which requires the measurement and recognition of expected credit losses for financial assets held at amortized cost, which includes the Company's accounts receivables, certain financial instruments and contract assets. ASU No. 2016-13 replaces the existing incurred loss impairment model with an expected loss methodology, which will result in more timely recognition of credit losses. For available-for-sale debt securities, credit losses should be recorded through an allowance for credit losses. ASU No. 2016-13 becomes effective for the Company for the fiscal year beginning February 1, 2020 and requires a cumulative effect adjustment to the balance sheet as of the beginning of the first reporting period in which the guidance is effective. The Company is currently evaluating the impact of the adoption of this standard on its condensed consolidated financial statements.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Oct. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The following tables present information about the Company’s financial assets that have been measured at fair value on a recurring basis as of October 31, 2019 and January 31, 2019 , and indicate the fair value hierarchy of the valuation inputs utilized to determine such fair value (in thousands): Fair Value Measurement at October 31, 2019 Level 1 Level 2 Level 3 Total Financial Assets: Cash and cash equivalents: Money market funds $ 98,183 $ — $ — $ 98,183 Short-term investments: U.S. government treasury securities 274,560 — — 274,560 Total financial assets $ 372,743 $ — $ — $ 372,743 Fair Value Measurement at January 31, 2019 Level 1 Level 2 Level 3 Total Financial Assets: Cash and cash equivalents: Money market funds $ 88,015 $ — $ — $ 88,015 Short-term investments: U.S. government treasury securities 318,139 — — 318,139 Total financial assets $ 406,154 $ — $ — $ 406,154 The Company utilized the market approach and Level 1 valuation inputs to value its money market mutual funds and U.S. government treasury securities because published net asset values were readily available. As of October 31, 2019 and January 31, 2019 , gross unrealized gains and unrealized losses for cash equivalents and short-term investments were not material, and the contractual maturity of all marketable securities was less than one year. In addition to its cash, cash equivalents and short-term investments, the Company measures the fair value of its outstanding Notes (as defined below) on a quarterly basis for disclosure purposes. The Company considers the fair value of the Notes at October 31, 2019 to be a Level 2 measurement due to limited trading activity of the Notes. Refer to Note 6, Convertible Senior Notes , to the condensed consolidated financial statements for further details.

Business Combinations

Business Combinations	9 Months Ended
	Oct. 31, 2019
Business Combinations [Abstract]
Business Combinations	Business Combinations The Company acquired all of the issued and outstanding capital stock of Tightdb, Inc. (“Realm”) on May 7, 2019 (the “Acquisition Date”) for a purchase price of $39.0 million in cash, subject to working capital, cash, debt, transaction expenses and other closing adjustments. Realm, based in San Francisco, California, offers a mobile database, as well as a platform with real-time data synchronization between mobile applications and cloud databases. The Company used the acquisition method to account for the purchase of Realm, which met the definition of a business. As of October 31, 2019 , the Company had finalized the working capital, cash, debt, transaction expenses and other closing adjustments and identified and recorded the fair value of the assets and liabilities acquired, as well as the residual value to goodwill. The allocation of the purchase price was based on available information and assumptions at the time of the initial valuation and may be subject to change within the measurement period. The total merger consideration, after closing adjustments, was $38.8 million , which included adjustments for cash and working capital. The following table represents a summary of the purchase price (in thousands): Amounts Purchase price pursuant to the merger agreement $ 39,000 Estimated cash amount 115 Downward closing working capital adjustment (352 ) Total purchase price to be allocated $ 38,763 The following table summarizes the purchase price allocation fair values of the assets acquired and liabilities and the value of goodwill assumed at the Acquisition Date (in thousands): Estimated Fair Value Financial and tangible assets, net $ 43 Identifiable intangible asset - developed technology 27,300 Identifiable intangible asset - customer relationships 1,700 Deferred revenue (350 ) Goodwill (excluding deferred tax liability impact) 10,070 Total purchase price $ 38,763 Financial and tangible assets, net primarily include the cash acquired and accounts receivable, net of existing Realm obligations as of the Acquisition Date. Developed technology includes both the Realm mobile database and the Realm Object Server, which together automatically synchronize data between mobile applications and cloud databases, including MongoDB Atlas. The Company determined the economic useful life to be five years based on expected time period that the asset would contribute to the Company’s future cash flows without significant upgrades. The fair value of developed technology was estimated using the reproduction cost method (Level 3), which utilized assumptions for the cost to replace, such as the workforce, timing and resources required, as well as a theoretical profit margin and opportunity cost. Customer relationships represent the fair value of projected subscription revenue that is expected to be generated from existing customers of Realm as of the Acquisition Date. The Company determined the economic useful life to be five years and the fair value of customer relationships was estimated using the replacement cost approach (Level 3), which utilized assumptions for sales and marketing expenses to determine the estimated cost to acquire a Realm customer. Other assumptions include a theoretical profit margin and opportunity costs. These two intangible assets acquired are being amortized over their estimated useful lives using the straight-line method of amortization, which approximates the distribution of the economic value of the identified intangible assets. See Note 5, Goodwill and Acquired Intangible Assets, Net , for further details Deferred revenue was estimated at fair value under the cost build-up method (Level 3), which was determined based on estimated direct and indirect costs to support and fulfill the subscription obligation plus an assumed operating margin. Deferred revenue will be recognized based on the revenue criteria set forth in Note 2, Summary of Significant Accounting Policies , in the Company’s 2019 Form 10-K. Goodwill related to the acquisition, which represents the difference between the purchase price and fair values of identifiable net assets, is primarily attributable to assembled workforce, as well as expected synergies of the combination. The goodwill is no t tax deductible for U.S. income tax purposes. In addition to the goodwill recorded through the purchase price allocation disclosed in the table above, the Company recorded an additional $3.5 million to goodwill resulting from deferred tax liabilities associated with the acquired intangible assets. Refer to Note 12, Income Taxes , for further discussion of the tax impact of the acquisition. The Company incurred acquisition-related costs for the Realm acquisition of $0.6 million during the nine months ended October 31, 2019 . These acquisition-related costs were included in general and administrative expenses in the Company’s condensed consolidated statements of operations. The Company included Realm’s estimated fair value of assets acquired and liabilities assumed in its condensed consolidated balance sheet beginning on the Acquisition Date. The results of operations for Realm subsequent to the Acquisition Date have been included in, but are not material to, the Company's condensed consolidated statements of operations for the three and nine months ended October 31, 2019 . The pro forma results of operations for the Realm acquisition have not been presented because they were not material to the Company’s condensed consolidated statements of operations for the three and nine months ended October 31, 2019 and 2018 .

Goodwill and Acquired Intangibl

Goodwill and Acquired Intangible Assets, Net	9 Months Ended
	Oct. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Acquired Intangible Assets, Net	Goodwill and Acquired Intangible Assets, Net The following table summarizes the changes in the carrying amount of goodwill during the periods presented (in thousands): Balance, January 31, 2019 $ 41,878 Increase in goodwill related to business combinations 13,606 Balance, October 31, 2019 $ 55,484 Refer to Note 4, Business Combinations , for further details on the addition to goodwill. The gross carrying amount and accumulated amortization of the Company’s intangible assets are as follows (in thousands): October 31, 2019 Gross Carrying Value Accumulated Amortization Net Book Value Developed technology $ 34,700 $ (10,058 ) $ 24,642 Domain name 155 (145 ) 10 Customer relationships 15,200 (2,870 ) 12,330 Total $ 50,055 $ (13,073 ) $ 36,982 January 31, 2019 Gross Carrying Value Accumulated Amortization Net Book Value Developed technology $ 7,400 $ (4,358 ) $ 3,042 Domain name 155 (128 ) 27 Customer relationships 13,500 (675 ) 12,825 Total $ 21,055 $ (5,161 ) $ 15,894 Acquired intangible assets are amortized on a straight-line basis. As of October 31, 2019 , the weighted-average remaining useful lives of identifiable, acquisition-related intangible assets was 4.5 years for developed technology, 0.4 years for domain name and 4.1 years for customer relationships. Amortization expense of intangible assets was $3.1 million and $7.9 million for the three and nine months ended October 31, 2019 , respectively. Amortization expense for developed technology and the domain name was included as research and development expense in the Company’s condensed consolidated statements of operations. Amortization expense for customer relationships was included as sales and marketing expense in the Company’s condensed consolidated statements of operations. As of October 31, 2019 , future amortization expense related to the intangible assets is as follows (in thousands): Years Ending January 31, Remainder of 2020 $ 2,202 2021 8,504 2022 8,500 2023 8,500 2024 7,825 2025 1,451 Total $ 36,982

Convertible Senior Notes

Convertible Senior Notes	9 Months Ended
	Oct. 31, 2019
Debt Disclosure [Abstract]
Convertible Senior Notes	Convertible Senior Notes In June 2018, the Company issued $250.0 million aggregate principal amount of 0.75% convertible senior notes due 2024 (the “Notes”) in a private placement and, in July 2018, the Company issued an additional $50.0 million aggregate principal amount of the Notes pursuant to the exercise in full of the initial purchasers’ option to purchase additional Notes. The Notes are senior unsecured obligations of the Company, and interest is payable semiannually in arrears on June 15 and December 15 of each year, beginning on December 15, 2018, at a rate of 0.75% per year. The Notes will mature on June 15, 2024, unless earlier converted, redeemed or repurchased. The total net proceeds from the offering, after deducting initial purchase discounts and estimated debt issuance costs, were approximately $291.1 million . The initial conversion rate is 14.6738 shares of the Company’s Class A common stock per $1,000 principal amount of Notes, which is equal to an initial conversion price of approximately $68.15 per share of Class A common stock, subject to adjustment upon the occurrence of specified events. The Notes will be convertible at the option of the holders at any time prior to the close of business on the business day immediately preceding March 15, 2024, only under the following circumstances: (1) during any fiscal quarter commencing after the fiscal quarter ending on October 31, 2018 (and only during such fiscal quarter), if the last reported sale price of the Company’s Class A common stock for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding fiscal quarter is greater than or equal to 130% of the conversion price of the Notes on each applicable trading day; (2) during the five -business day period after any five consecutive trading day period (the “measurement period”) in which the trading price per $1,000 principal amount of the Notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price of the Company’s Class A common stock and the conversion rate of the Notes on each such trading day; (3) if the Company calls any or all of the Notes for redemption, at any time prior to the close of business on the scheduled trading day immediately preceding the redemption date; or (4) upon the occurrence of specified corporate events (as set forth in the indenture governing the Notes). On or after March 15, 2024, until the close of business on the scheduled trading day immediately preceding the maturity date, holders may convert all or any portion of their Notes, in multiples of $1,000 principal amount, at the option of the holder, regardless of the foregoing circumstances. Upon conversion, the Company will satisfy its conversion obligation by paying or delivering, as the case may be, cash, shares of the Company’s Class A common stock or a combination of cash and shares of the Company’s Class A common stock, at the Company’s election. If a fundamental change (as defined in the indenture governing the Notes) occurs prior to the maturity date, holders of the Notes will have the right to require the Company to repurchase for cash all or any portion of their Notes at a repurchase price equal to 100% of the principal amount of the Notes to be repurchased, plus accrued and unpaid interest to, but excluding, the fundamental change repurchase date. In addition, if specific corporate events occur prior to the applicable maturity date, or if the Company elects to redeem the Notes, the Company will increase the conversion rate for a holder who elects to convert their notes in connection with such a corporate event or redemption in certain circumstances. It is the Company’s current intent to settle the principal amount of the Notes in cash. During the three months ended October 31, 2019 , the conditional conversion feature of the Notes was triggered as the last reported sale price of the Company's Class A common stock was more than or equal to 130% of the conversion price for at least 20 trading days in the period of 30 consecutive trading days ending on October 31, 2019 (the last trading day of the fiscal quarter), and therefore the Notes are currently convertible, in whole or in part, at the option of the holders between November 1, 2019 through January 31, 2020. Whether the Notes will be convertible following such period will depend on the continued satisfaction of this condition or another conversion condition in the future. As of October 31, 2019 , the Company had not received any conversion notices. Since the Company has the election of repaying the Notes in cash, shares of the Company’s Class A common stock, or a combination of both, the Company continued to classify the Notes as long-term debt on the Company’s condensed consolidated balance sheet as of October 31, 2019 . The Company may not redeem the Notes prior to June 20, 2021. On or after June 20, 2021, the Company may redeem for cash all or any portion of the Notes, at its option, if the last reported sale price of its Class A common stock was at least 130% of the conversion price then in effect for at least 20 trading days (whether or not consecutive) during any 30 consecutive trading day period (including the last trading day of such period) ending on, and including, the trading day immediately preceding the date on which the Company provides a notice of redemption at a redemption price equal to 100% of the principal amount of the Notes to be redeemed, plus accrued and unpaid interest to, but excluding, the redemption date. In accounting for the issuance of the Notes, the Notes were separated into liability and equity components. The carrying amounts of the liability component was calculated by measuring the fair value of similar liabilities that do not have associated convertible features. The carrying amount of the equity component representing the conversion option was determined by deducting the fair value of the liability component from the par value of the respective Notes. This difference represents the debt discount that is amortized to interest expense over the respective terms of the Notes using the effective interest rate method. The carrying amount of the equity component representing the conversion option was determined to be $84.2 million . The equity component was recorded in additional paid-in capital and is not remeasured as long as it continues to meet the conditions for equity classification. In accounting for the debt issuance costs of $8.8 million related to the Notes, the Company allocated the total amount incurred to the liability and equity components of the Notes based on their relative values. Issuance costs attributable to the liability component were $6.3 million and will be amortized, along with the debt discount, to interest expense over the contractual term of the Notes at an effective interest rate of 7.03% . Issuance costs attributable to the equity component were $2.5 million and are netted against the equity component representing the conversion option in additional paid-in capital. The net carrying amount of the liability component of the Notes was as follows (in thousands): October 31, 2019 Principal $ 300,000 Unamortized debt discount (67,964 ) Unamortized debt issuance costs (5,346 ) Net carrying amount $ 226,690 The net carrying amount of the equity component of the Notes was as follows (in thousands): October 31, 2019 Debt discount for conversion option $ 84,168 Issuance costs (2,485 ) Net carrying amount $ 81,683 As of October 31, 2019 , the total estimated fair value of the Notes was approximately $570.0 million . The fair value was determined based on the closing trading price per $100 of the Notes as of the last day of trading for the period. The fair value of the Notes is primarily affected by the trading price of the Company’s common stock and market interest rates. The following table sets forth the interest expense related to the Notes (in thousands): Three Months Ended October 31, Nine Months Ended October 31, 2019 2018 2019 2018 Contractual interest expense $ 563 $ 563 $ 1,688 $ 763 Amortization of debt discount 3,132 2,938 9,248 3,971 Amortization of issuance costs 202 174 585 234 Total $ 3,897 $ 3,675 $ 11,521 $ 4,968 Capped Calls In connection with the pricing of the Notes, the Company entered into privately negotiated capped call transactions with certain counterparties (the “Capped Calls”). The Capped Calls each have an initial strike price of approximately $68.15 per share, subject to certain adjustments, which corresponds to the initial conversion price of the Notes. The Capped Calls have initial cap prices of $106.90 per share, subject to certain adjustments. The Capped Calls are expected to partially offset the potential dilution to the Company’s Class A common stock upon any conversion of the Notes, with such offset subject to a cap based on the cap price. The Capped Calls cover, subject to anti-dilution adjustments, approximately 4.4 million shares of the Company’s Class A common stock. The Capped Calls are subject to adjustment upon the occurrence of specified extraordinary events affecting the Company, including merger events, tender offers and the announcement of such events. In addition, the Capped Calls are subject to certain specified additional disruption events that may give rise to a termination of the Capped Calls, including nationalization, insolvency or delisting, changes in law, failures to deliver, insolvency filings and hedging disruptions. For accounting purposes, the Capped Calls are separate transactions, and not part of the terms of the Notes. As these transactions meet certain accounting criteria, the Capped Calls are recorded in stockholders' equity and are not accounted for as derivatives. The cost of $37.1 million incurred to purchase the Capped Calls was recorded as a reduction to additional paid-in capital and will not be remeasured.

Leases

Leases	9 Months Ended
	Oct. 31, 2019
Leases [Abstract]
Leases	Leases Finance Lease In December 2017, the Company entered into a lease agreement for 106,230 rentable square feet of office space (the “Premises”) to accommodate its growing employee base in New York City. The Company received delivery of the Premises on January 1, 2018 to commence construction to renovate the Premises. Total estimated aggregate base rent payments over the initial 12 -year term of the lease are $87.3 million and payments began in July 2019. The Company has the option to extend the term of the lease by an additional 5 years . Operating Leases The Company has entered into non-cancelable operating leases, primarily related to rental of office space expiring through 2029. The Company recognizes operating lease costs on a straight-line basis over the term of the agreement, taking into account adjustments for market provisions such as free or escalating base monthly rental payments or deferred payment terms such as rent holidays that defer the commencement date of the required payments. The Company may receive renewal or expansion options, leasehold improvement allowances or other incentives on certain lease agreements. Lease Costs The components of the Company’s lease costs included in its condensed consolidated statement of operations were as follows (in thousands): Three Months Ended October 31, 2019 Nine Months Ended October 31, 2019 Finance lease cost: Amortization of right-of-use assets $ 994 $ 2,982 Interest on lease liabilities 916 2,739 Operating lease cost 1,152 3,505 Short-term lease cost 785 1,488 Total lease cost $ 3,847 $ 10,714 Balance Sheet Components The balances of the Company’s finance and operating leases were recorded on the condensed consolidated balance sheet as follows (in thousands): October 31, 2019 Finance Lease: Property and equipment, net $ 40,405 Other accrued liabilities 4,568 Other liabilities, non-current 60,439 Operating Leases: Operating lease right-of-use assets $ 12,151 Operating lease liabilities (current) 4,180 Operating lease liabilities, non-current 9,044 Supplemental Information The following table presents supplemental information related to the Company’s finance and operating leases (in thousands, except weighted-average information): Nine Months Ended October 31, 2019 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from finance lease $ 916 Operating cash flows from operating leases 3,204 Financing cash flows from finance lease 798 Right-of-use assets obtained in exchange for lease obligations: Finance lease $ — Operating leases 3,930 Weighted-average remaining lease term (in years): Finance lease 10.2 Operating leases 4.3 Weighted-average discount rate: Finance lease 5.6 % Operating leases 6.1 % Maturities of Lease Liabilities Future minimum lease payments under non-cancelable finance and operating leases on an annual undiscounted cash flow basis as of October 31, 2019 were as follows (in thousands): Year Ending January 31, Finance Lease Operating Leases Remainder of 2020 $ 2,018 $ 1,634 2021 8,073 5,163 2022 8,073 2,957 2023 8,073 2,730 2024 8,073 1,276 Thereafter 51,274 2,254 Total minimum payments 85,584 16,014 Less imputed interest (20,577 ) (2,790 ) Present value of future minimum lease payments 65,007 13,224 Less current obligations under leases (4,568 ) (4,180 ) Non-current lease obligations $ 60,439 $ 9,044 Excluded in the lease obligation table above is a new agreement to lease an additional 21,000 square feet of office space in New York City, which will be recognized as an operating lease upon the lease commencement date. The Company entered into this agreement in October 2019 and expects the lease to commence on or around April 2020 for a term of five years with no renewal period. The total estimated aggregate base rent payments are $8.1 million with payments beginning four months subsequent to the commencement date. Future minimum lease payments under non-cancelable financing and operating leases, based on the previous lease accounting standard, as of January 31, 2019, were as follows (in thousands): Year Ending January 31, Financing Lease Operating Leases 2020 $ 3,732 $ 4,578 2021 8,073 3,765 2022 8,073 2,277 2023 8,073 2,224 2024 8,073 922 Thereafter 51,274 2,149 Total minimum payments $ 87,298 $ 15,915
Leases	Leases Finance Lease In December 2017, the Company entered into a lease agreement for 106,230 rentable square feet of office space (the “Premises”) to accommodate its growing employee base in New York City. The Company received delivery of the Premises on January 1, 2018 to commence construction to renovate the Premises. Total estimated aggregate base rent payments over the initial 12 -year term of the lease are $87.3 million and payments began in July 2019. The Company has the option to extend the term of the lease by an additional 5 years . Operating Leases The Company has entered into non-cancelable operating leases, primarily related to rental of office space expiring through 2029. The Company recognizes operating lease costs on a straight-line basis over the term of the agreement, taking into account adjustments for market provisions such as free or escalating base monthly rental payments or deferred payment terms such as rent holidays that defer the commencement date of the required payments. The Company may receive renewal or expansion options, leasehold improvement allowances or other incentives on certain lease agreements. Lease Costs The components of the Company’s lease costs included in its condensed consolidated statement of operations were as follows (in thousands): Three Months Ended October 31, 2019 Nine Months Ended October 31, 2019 Finance lease cost: Amortization of right-of-use assets $ 994 $ 2,982 Interest on lease liabilities 916 2,739 Operating lease cost 1,152 3,505 Short-term lease cost 785 1,488 Total lease cost $ 3,847 $ 10,714 Balance Sheet Components The balances of the Company’s finance and operating leases were recorded on the condensed consolidated balance sheet as follows (in thousands): October 31, 2019 Finance Lease: Property and equipment, net $ 40,405 Other accrued liabilities 4,568 Other liabilities, non-current 60,439 Operating Leases: Operating lease right-of-use assets $ 12,151 Operating lease liabilities (current) 4,180 Operating lease liabilities, non-current 9,044 Supplemental Information The following table presents supplemental information related to the Company’s finance and operating leases (in thousands, except weighted-average information): Nine Months Ended October 31, 2019 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from finance lease $ 916 Operating cash flows from operating leases 3,204 Financing cash flows from finance lease 798 Right-of-use assets obtained in exchange for lease obligations: Finance lease $ — Operating leases 3,930 Weighted-average remaining lease term (in years): Finance lease 10.2 Operating leases 4.3 Weighted-average discount rate: Finance lease 5.6 % Operating leases 6.1 % Maturities of Lease Liabilities Future minimum lease payments under non-cancelable finance and operating leases on an annual undiscounted cash flow basis as of October 31, 2019 were as follows (in thousands): Year Ending January 31, Finance Lease Operating Leases Remainder of 2020 $ 2,018 $ 1,634 2021 8,073 5,163 2022 8,073 2,957 2023 8,073 2,730 2024 8,073 1,276 Thereafter 51,274 2,254 Total minimum payments 85,584 16,014 Less imputed interest (20,577 ) (2,790 ) Present value of future minimum lease payments 65,007 13,224 Less current obligations under leases (4,568 ) (4,180 ) Non-current lease obligations $ 60,439 $ 9,044 Excluded in the lease obligation table above is a new agreement to lease an additional 21,000 square feet of office space in New York City, which will be recognized as an operating lease upon the lease commencement date. The Company entered into this agreement in October 2019 and expects the lease to commence on or around April 2020 for a term of five years with no renewal period. The total estimated aggregate base rent payments are $8.1 million with payments beginning four months subsequent to the commencement date. Future minimum lease payments under non-cancelable financing and operating leases, based on the previous lease accounting standard, as of January 31, 2019, were as follows (in thousands): Year Ending January 31, Financing Lease Operating Leases 2020 $ 3,732 $ 4,578 2021 8,073 3,765 2022 8,073 2,277 2023 8,073 2,224 2024 8,073 922 Thereafter 51,274 2,149 Total minimum payments $ 87,298 $ 15,915

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Oct. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Non-cancelable Material Commitments During the nine months ended October 31, 2019 , there have been no material changes outside the ordinary course of business to the Company’s contractual obligations and commitments from those disclosed in the 2019 Form 10-K. Legal Matters From time to time, the Company has become involved in claims, litigation and other legal matters arising in the ordinary course of business, including intellectual property claims, labor and employment claims and breach of contract claims. For example, on March 12, 2019, Realtime Data (“Realtime”) filed a lawsuit against the Company in the United States District Court for the District of Delaware alleging that the Company is infringing three U.S. patents that it holds: U.S. Patent No. 9,116,908, U.S. Patent No. 9,667,751 and U.S. Patent No. 8,933,825. The patent infringement allegations in the lawsuit relate to data compression, decompression, storage and retrieval. Realtime seeks monetary damages and injunctive relief. In August 2019, the District Court approved the Company and Realtime’s stipulation to stay Realtime’s lawsuit against the Company pending the outcome of Realtime's appeal of the District Court's decision to invalidate two of the asserted patents in a separate action. The Company investigates claims, litigation and other legal matters as they arise. Although claims and litigation are inherently unpredictable, the Company is currently not aware of any matters that, if determined adversely to the Company, would individually or taken together have a material adverse effect on its business, financial position, results of operations or cash flows. The Company accrues estimates for resolution of legal and other contingencies when losses are probable and estimable. Although the results of claims and litigation are inherently unpredictable, the Company believes that there was less than a reasonable possibility that the Company had incurred a material loss with respect to such loss contingencies, as of October 31, 2019 and January 31, 2019 , therefore, the Company has no t recorded an accrual for such contingencies. Indemnification The Company enters into indemnification provisions under its agreements with other companies in the ordinary course of business, including business partners, landlords, contractors and parties performing its research and development. Pursuant to these arrangements, the Company agrees to indemnify, hold harmless and reimburse the indemnified party for certain losses suffered or incurred by the indemnified party as a result of the Company’s activities. The terms of these indemnification agreements are generally perpetual. The maximum potential amount of future payments the Company could be required to make under these agreements is not determinable. The Company has never incurred costs to defend lawsuits or settle claims related to these indemnification agreements. As a result, the Company believes the fair value of these agreements is not material. The Company maintains commercial general liability insurance and product liability insurance to offset certain of the Company’s potential liabilities under these indemnification provisions. The Company has entered into indemnification agreements with each of its directors and executive officers. These agreements require the Company to indemnify such individuals, to the fullest extent permitted by Delaware law, for certain liabilities to which they may become subject as a result of their affiliation with the Company.

Revenue

Revenue	9 Months Ended
	Oct. 31, 2019
Revenues [Abstract]
Revenue	Revenue Disaggregation of Revenue Based on the information provided to and reviewed by the Company’s Chief Executive Officer, the Company believes that the nature, amount, timing and uncertainty of its revenue and cash flows and how they are affected by economic factors is most appropriately depicted through the Company’s primary geographical markets and subscription product categories. The Company’s primary geographical markets are North and South America (“Americas”); Europe, Middle East and Africa (“EMEA”); and Asia Pacific. The Company also disaggregates its subscription products between its MongoDB Atlas-related offerings, which includes mLab, and other subscription products, which includes MongoDB Enterprise Advanced. The following table presents the Company’s revenues disaggregated by primary geographical markets, subscription product categories and services (in thousands): Three Months Ended October 31, Nine Months Ended October 31, 2019 2018 2019 2018 Primary geographical markets: Americas $ 71,332 $ 43,570 $ 194,055 $ 115,726 EMEA 30,374 24,406 83,504 56,367 Asia Pacific 7,735 3,806 20,638 9,439 Total $ 109,441 $ 71,782 $ 298,197 $ 181,532 Subscription product categories and services: MongoDB Atlas-related $ 44,133 $ 15,375 $ 111,783 $ 32,945 Other subscription 59,694 51,229 170,194 134,814 Services 5,614 5,178 16,220 13,773 Total $ 109,441 $ 71,782 $ 298,197 $ 181,532 Customers located in the United States accounted for 61% and 60% of total revenue for the three and nine months ended October 31, 2019 , respectively, and 57% and 60% of total revenue for the three and nine months ended October 31, 2018 , respectively. Customers located in the United Kingdom accounted for 9% and 10% of total revenue for the three and nine months ended October 31, 2019 , respectively, and 10% for both the three and nine months ended October 31, 2018 . No other country accounted for 10% or more of revenue for the periods presented. As of October 31, 2019 and 2018 , substantially all of the Company’s long-lived assets were located in the United States. Contract Liabilities The Company’s contract liabilities are recorded as deferred revenue in the Company’s consolidated balance sheet and consists of customer invoices issued or payments received in advance of revenues being recognized from the Company’s subscription and services contracts. Deferred revenue, including current and non-current balances, as of October 31, 2019 and January 31, 2019 was $152.4 million and $137.7 million , respectively. For the nine months ended October 31, 2019 and 2018 , revenue recognized from deferred revenue at the beginning of each period was $109.6 million and $73.5 million , respectively. Remaining Performance Obligations Remaining performance obligations represent the aggregate amount of the transaction price in contracts allocated to performance obligations not delivered, or partially undelivered, as of the end of the reporting period. Remaining performance obligations include unearned revenue, multi-year contracts with future installment payments and certain unfulfilled orders against accepted customer contracts at the end of any given period. As of October 31, 2019 , the aggregate transaction price allocated to remaining performance obligations was $187.8 million . Approximately 53% is expected to be recognized as revenue over the next 12 months and the remainder thereafter. The Company applied the practical expedient to omit disclosure with respect to the amount of the transaction price allocated to remaining performance obligations if the related contract has a total duration of 12 months or less. Unbilled Receivables Revenue recognized in excess of invoiced amounts creates an unbilled receivable, which represents the Company’s unconditional right to consideration in exchange for goods or services that the Company has transferred to the customer. Unbilled receivables were recorded as part of accounts receivable, net in the Company’s consolidated balance sheets. As of October 31, 2019 , unbilled receivables were $9.0 million . Costs Capitalized to Obtain Contracts with Customers The Company capitalizes the incremental costs that are directly associated with non-cancelable subscription contracts with customers and consist of sales commissions paid to the Company’s sales force, which were recorded as deferred commissions and other assets, depending on the expected length of the deferral, in the Company’s consolidated balance sheets. Deferred commissions were $60.8 million as of October 31, 2019 . Amortization expense with respect to deferred commissions was $4.9 million and $13.9 million for the three and nine months ended October 31, 2019 , respectively, and $3.6 million and $10.2 million for the three and nine months ended October 31, 2018 , respectively. There was no impairment loss in relation to the costs capitalized for the periods presented.

Equity Incentive Plans and Empl

Equity Incentive Plans and Employee Stock Purchase Plan	9 Months Ended
	Oct. 31, 2019
Share-based Payment Arrangement [Abstract]
Equity Incentive Plans and Employee Stock Purchase Plan	Equity Incentive Plans and Employee Stock Purchase Plan 2008 Stock Incentive Plan and 2016 Equity Incentive Plan The Company adopted the 2008 Stock Incentive Plan (as amended, the “2008 Plan”) in 2008 and the 2016 Equity Incentive Plan (as amended, the “2016 Plan”) in 2016, primarily for the purpose of granting stock-based awards to employees, directors and consultants. With the establishment of the 2016 Plan in December 2016, all shares available for grant under the 2008 Plan were transferred to the 2016 Plan. The Company no longer grants any stock-based awards under the 2008 Plan and any shares underlying stock options canceled under the 2008 Plan will be automatically transferred to the 2016 Plan. Stock Options The 2016 Plan provides for the issuance of incentive stock options to employees and nonstatutory stock options to employees, directors or consultants. The Company’s Board of Directors or a committee thereof determines the vesting schedule for all equity awards. Stock option awards generally vest over a period of four years with 25% vesting on the one-year anniversary of the award and the remainder vesting monthly over the next 36 months of the grantee’s service to the Company. The following table summarizes stock option activity for the nine months ended October 31, 2019 (in thousands, except share and per share data and years): Shares Weighted- Weighted- Aggregate Balance - January 31, 2019 8,621,010 $ 7.75 6.7 $ 729,392 Stock options exercised (1,729,833 ) 7.67 Stock options forfeited and expired (208,258 ) 11.56 Balance - October 31, 2019 6,682,919 $ 7.66 5.9 $ 802,710 Vested and exercisable - January 31, 2019 5,342,183 $ 6.95 6.0 $ 456,275 Vested and exercisable - October 31, 2019 4,790,453 $ 7.07 5.5 $ 578,198 Restricted Stock Units The 2016 Plan provides for the issuance of restricted stock units (“RSUs”) to employees, directors and consultants. RSUs granted to new employees generally vest over a period of four years with 25% vesting on the one-year anniversary of the vesting start date and the remainder vesting quarterly over the next 12 quarters, subject to the grantee’s continued service to the Company. RSUs granted to existing employees generally vest quarterly over a period of four years , subject to the grantee’s continued service to the Company. The following table summarizes RSU activity for the nine months ended October 31, 2019 : Shares Weighted-Average Grant Date Fair Value per RSU Unvested - January 31, 2019 1,988,774 $ 54.22 RSUs granted 1,530,227 118.47 RSUs vested (541,132 ) 62.07 RSUs forfeited and canceled (212,881 ) 78.30 Unvested - October 31, 2019 2,764,988 $ 86.38 2017 Employee Stock Purchase Plan In October 2017, the Company’s Board of Directors adopted, and stockholders approved, the 2017 Employee Stock Purchase Plan (the “2017 ESPP”). A total of 2.0 million shares of the Company’s Class A common stock have been authorized for issuance under the 2017 ESPP. Subject to any plan limitations, the 2017 ESPP allows eligible employees to contribute, normally through payroll deductions, up to 15% of their earnings for the purchase of the Company’s Class A common stock at a discounted price per share. The Company’s current offering period began June 17, 2019 and is expected to end December 13, 2019. Stock-Based Compensation Expense Total stock-based compensation expense recognized in the Company’s unaudited condensed consolidated statements of operations is as follows (in thousands): Three Months Ended October 31, Nine Months Ended October 31, 2019 2018 2019 2018 Cost of revenue—subscription $ 1,274 $ 555 $ 3,476 $ 1,403 Cost of revenue—services 793 335 2107 800 Sales and marketing 6,844 3,090 17,728 7,437 Research and development 6,879 3,131 17,513 8,241 General and administrative 3,577 3,153 10,214 8,969 Total stock-based compensation expense $ 19,367 $ 10,264 $ 51,038 $ 26,850

Net Loss Per Share

Net Loss Per Share	9 Months Ended
	Oct. 31, 2019
Earnings Per Share [Abstract]
Net Loss Per Share	Net Loss Per Share The Company calculates basic net loss per share by dividing the net loss by the weighted-average number of shares of common stock outstanding during the period, less shares subject to repurchase. Diluted net loss per share is computed by giving effect to all potentially dilutive common stock equivalents outstanding for the period, including stock options and restricted stock units. Basic and diluted net loss per share was the same for each period presented, as the inclusion of all potential common shares outstanding would have been anti-dilutive due to the net loss reported for each period presented. The rights, including the liquidation and dividend rights, of the holders of Class A and Class B common stock are identical, except with respect to voting. Each share of Class A common stock is entitled to one vote per share and each share of Class B common stock is entitled to 10 votes per share. As the liquidation and dividend rights are identical for Class A and Class B common stock, the undistributed earnings are allocated on a proportionate basis and the resulting net loss per share will, therefore, be the same for both Class A and Class B common stock on an individual or combined basis. The following table sets forth the computation of basic and diluted net loss per share (in thousands, except share and per share data): Three Months Ended October 31, Nine Months Ended October 31, 2019 2018 2019 2018 Numerator: Net loss $ (42,383 ) $ (22,487 ) $ (112,959 ) $ (76,824 ) Denominator: Weighted-average shares used to compute net loss per share, basic and diluted 56,411,779 52,702,526 55,600,484 51,431,021 Net loss per share, basic and diluted $ (0.75 ) $ (0.43 ) $ (2.03 ) $ (1.49 ) The shares underlying the conversion option in the Notes were not considered in the calculation of diluted net loss per share as the effect would have been anti-dilutive. Based on the initial conversion price, the entire outstanding principal amount of the Notes as of October 31, 2019 would have been convertible into approximately 4.4 million shares of the Company’s Class A common stock. However, the Company currently expects to settle the principal amount of the Notes in cash. As a result, only the amount by which the conversion value exceeds the aggregate principal amount of the Notes (the “conversion spread”) is considered in the diluted earnings per share computation under the treasury stock method. The conversion spread has a dilutive impact on diluted net income per share when the average market price of the Company’s Class A common stock for a given period exceeds the initial conversion price of $68.15 per share for the Notes. In connection with the issuance of the Notes, the Company entered into Capped Calls, which were not included for purposes of calculating the number of diluted shares outstanding, as their effect would have been anti-dilutive. The Capped Calls are expected to partially offset the potential dilution to the Company’s Class A common stock upon any conversion of the Notes. During the three months ended October 31, 2019 , the average market price of the Company’s Class A common stock was $134.49 , which exceeded the initial conversion price. The Company had not received any conversion notices through the issuance date of these unaudited condensed consolidated financial statements. For disclosure purposes, the Company calculated the potentially dilutive effect of the conversion spread, which is included in the table below. The following weighted-average outstanding potentially dilutive shares of common stock were excluded from the computation of diluted net loss per share for the periods presented because the impact of including them would have been anti-dilutive. Three Months Ended October 31, Nine Months Ended October 31, 2019 2018 2019 2018 Stock options to purchase Class A common stock 2,042,636 3,046,631 2,242,253 3,315,885 Stock options to purchase Class B common stock 4,805,226 7,137,570 5,230,288 8,136,949 Unvested restricted stock units 2,876,802 1,707,692 2,790,999 1,265,391 Early exercised stock options 22,940 94,026 33,900 146,248 Shares underlying the conversion spread in the convertible senior notes 2,171,371 215,879 2,175,450 71,960

Income Taxes

Income Taxes	9 Months Ended
	Oct. 31, 2019
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company recorded a provision (benefit) related to income taxes of $0.6 million and $(2.9) million for the three and nine months ended October 31, 2019, respectively, and $(0.03) million and $0.7 million for the three and nine months ended October 31, 2018, respectively. The overall benefit recorded during the nine months ended October 31, 2019 was driven by a net release of $3.5 million in the Company’s valuation allowance on deferred tax assets primarily as a result of deferred taxes recorded in purchase accounting as part of the Realm acquisition and excess tax deductions in the United Kingdom with respect to stock option exercises. The consolidated provision recorded during the three months ended October 31, 2019 was primarily due to foreign taxes. The Company assesses uncertain tax positions in accordance with ASC 740-10, Accounting for Uncertainties in Tax . As of October 31, 2019, the Company’s net unrecognized tax benefits totaled $4.6 million , of which $0.1 million would impact the Company’s effective tax rate if recognized. The Company anticipates that the amount of reasonably possible unrecognized tax benefits that could decrease over the next twelve months due to the expiration of certain statutes of limitations and settlement of tax audits is no t material to the Company’s interim unaudited condensed consolidated financial statements.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Oct. 31, 2019
Accounting Policies [Abstract]
Basis of Presentation	The interim unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and include the accounts of the Company and its wholly owned subsidiaries. All intercompany transactions and accounts have been eliminated. Certain information and note disclosures normally included in the financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to the applicable rules and regulations of the Securities and Exchange Commission. The condensed balance sheet data as of January 31, 2019 was derived from the Company’s audited financial statements, but does not include all disclosures required by U.S. GAAP. Therefore, these interim unaudited condensed consolidated financial statements and accompanying footnotes should be read in conjunction with the Company’s annual consolidated financial statements and related footnotes included in its Annual Report on Form 10-K for the fiscal year ended January 31, 2019 (the “2019 Form 10-K”).
Use of Estimates	The preparation of the interim unaudited condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. Such estimates include, but are not limited to, revenue recognition, allowances for doubtful accounts, stock-based compensation, legal contingencies, fair value of acquired intangible assets and goodwill, useful lives of acquired intangible assets and property and equipment, fair value of property and equipment and accounting for income taxes. The Company bases these estimates on historical and anticipated results, trends and various other assumptions that it believes are reasonable under the circumstances, including assumptions as to future events. Actual results could differ from those estimates.
Related Party Transactions	All contracts with related parties are executed in ordinary course of business.
New Accounting Pronouncements Not Yet Adopted	Leases. In February 2016, the Financial Accounting Standards Board issued ASU No. 2016-02, codified as Accounting Standards Codification 842 (“ASC 842”), which requires lessees to record the assets and liabilities arising from all leases, with the exception of short-term leases, on the balance sheet. Under ASC 842, lessees will recognize a liability for lease payments and a right-of-use asset. This guidance retains the distinction between finance leases and operating leases and the classification criteria for finance leases remains similar. For finance leases, a lessee will recognize the interest on a lease liability separate from amortization of the right-of-use asset. In addition, repayments of principal will be presented within financing activities, and interest payments will be presented within operating activities in the statement of cash flows. For operating leases, a lessee will recognize a single lease cost on a straight-line basis and classify all cash payments within operating activities in the statement of cash flows. The Company adopted the new lease accounting standard effective February 1, 2019 using the additional transition method described in ASU No. 2018-11, Leases – Targeted Improvements , which was issued in July 2018. Under the additional transition method, the Company recognized the cumulative effect of initially applying the guidance as an adjustment to the operating lease right-of-use assets and operating lease liabilities on its condensed consolidated balance sheet on February 1, 2019 without retrospective application to comparative periods. The adoption of ASC 842 resulted in recognition of right-of-use assets of $53.7 million , which included the impact of existing deferred rents of $2.9 million and lease liabilities of $70.2 million , along with a cumulative impact of $4.1 million on the opening accumulated deficit, as of February 1, 2019. The Company elected the package of practical expedients permitted under the transition guidance within ASC 842, which allowed the Company to carry forward its historical assessments of whether contracts are or contain leases, lease classification and initial direct costs. See Note 7, Leases , for additional details. The Company determines if an arrangement is, or contains, a lease at inception. Operating leases are disclosed separately on the condensed consolidated balance sheets and the finance lease is included in property and equipment, net, other accrued liabilities and other liabilities, non-current. The Company has elected an accounting policy to not recognize short-term leases (one year or less) on the consolidated balance sheet. Operating lease right-of-use assets and operating lease liabilities are recognized based on the present value of the lease payments over the lease term at commencement date. As most of the Company’s leases do not provide an implicit rate, the Company’s incremental borrowing rate is used based on the information available at commencement date in determining the present value of future payments. The operating lease right-of-use asset also includes any lease payments made and excludes lease incentives. Lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Lease expense for minimum lease payments is recognized on a straight-line basis over the lease term. Variable lease payments are expensed as incurred and are not included within the lease liability and right-of-use assets calculation. The Company accounts for lease components and non-lease components as a single lease component. Stock-Based Compensation. In June 2018, the FASB issued ASU No. 2018-07, Compensation - Stock Compensation (Topic 718): Improvements to Non-employee Share-Based Payment Accounting , which expands the scope of Topic 718 to include share-based payment transactions for acquiring goods and services from non-employees, with certain exceptions. The new guidance was effective for the Company for fiscal year beginning February 1, 2019 and the adoption had no material impact on its condensed consolidated financial statements. New Accounting Pronouncements Not Yet Adopted Goodwill Impairment. In January 2017, the FASB issued ASU No. 2017-04— Intangibles—Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment . The new standard simplifies the measurement of goodwill by eliminating step two of the two-step impairment test. Step two measures a goodwill impairment loss by comparing the implied fair value of a reporting unit’s goodwill with the carrying amount of that goodwill. The new guidance requires an entity to compare the fair value of a reporting unit with its carrying amount and recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value. Additionally, an entity should consider income tax effects from any tax-deductible goodwill on the carrying amount of the reporting unit when measuring the goodwill impairment loss, if applicable. The new guidance becomes effective for the Company for the fiscal year beginning February 1, 2020, though early adoption is permitted. The Company does not expect the adoption of the new accounting standard to have a material impact on its condensed consolidated financial statements. Cloud Computing. In August 2018, the FASB issued ASU No. 2018-15, Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract , which aligns the accounting for implementation costs incurred in a hosting arrangement that is a service contract with the accounting for implementation costs incurred to develop or obtain internal-use software under ASC 350-40, in order to determine which costs to capitalize and recognize as an asset and which costs to expense. ASU No. 2018-15 becomes effective for the Company for the fiscal year beginning February 1, 2020, with early adoption permitted, and can be applied either prospectively to implementation costs incurred after the date of adoption or retrospectively to all arrangements. The Company is currently evaluating the impact of the adoption of this standard on its condensed consolidated financial statements. Credit Losses. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments
Net Loss per Share	The Company calculates basic net loss per share by dividing the net loss by the weighted-average number of shares of common stock outstanding during the period, less shares subject to repurchase. Diluted net loss per share is computed by giving effect to all potentially dilutive common stock equivalents outstanding for the period, including stock options and restricted stock units. Basic and diluted net loss per share was the same for each period presented, as the inclusion of all potential common shares outstanding would have been anti-dilutive due to the net loss reported for each period presented. The rights, including the liquidation and dividend rights, of the holders of Class A and Class B common stock are identical, except with respect to voting. Each share of Class A common stock is entitled to one vote per share and each share of Class B common stock is entitled to 10 votes per share. As the liquidation and dividend rights are identical for Class A and Class B common stock, the undistributed earnings are allocated on a proportionate basis and the resulting net loss per share will, therefore, be the same for both Class A and Class B common stock on an individual or combined basis.
Income Taxes	The Company assesses uncertain tax positions in accordance with ASC 740-10, Accounting for Uncertainties in Tax

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Oct. 31, 2019
Fair Value Disclosures [Abstract]
Schedule of financial assets and liabilities measured at fair value on a recurring basis	The following tables present information about the Company’s financial assets that have been measured at fair value on a recurring basis as of October 31, 2019 and January 31, 2019 , and indicate the fair value hierarchy of the valuation inputs utilized to determine such fair value (in thousands): Fair Value Measurement at October 31, 2019 Level 1 Level 2 Level 3 Total Financial Assets: Cash and cash equivalents: Money market funds $ 98,183 $ — $ — $ 98,183 Short-term investments: U.S. government treasury securities 274,560 — — 274,560 Total financial assets $ 372,743 $ — $ — $ 372,743 Fair Value Measurement at January 31, 2019 Level 1 Level 2 Level 3 Total Financial Assets: Cash and cash equivalents: Money market funds $ 88,015 $ — $ — $ 88,015 Short-term investments: U.S. government treasury securities 318,139 — — 318,139 Total financial assets $ 406,154 $ — $ — $ 406,154

Business Combinations (Tables)

Business Combinations (Tables)	9 Months Ended
	Oct. 31, 2019
Business Combinations [Abstract]
Summary of US GAAP purchase price	The following table represents a summary of the purchase price (in thousands): Amounts Purchase price pursuant to the merger agreement $ 39,000 Estimated cash amount 115 Downward closing working capital adjustment (352 ) Total purchase price to be allocated $ 38,763
Schedule of purchase price allocation	The following table summarizes the purchase price allocation fair values of the assets acquired and liabilities and the value of goodwill assumed at the Acquisition Date (in thousands): Estimated Fair Value Financial and tangible assets, net $ 43 Identifiable intangible asset - developed technology 27,300 Identifiable intangible asset - customer relationships 1,700 Deferred revenue (350 ) Goodwill (excluding deferred tax liability impact) 10,070 Total purchase price $ 38,763

Goodwill and Acquired Intangi_2

Goodwill and Acquired Intangible Assets, Net (Tables)	9 Months Ended
	Oct. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of goodwill	The following table summarizes the changes in the carrying amount of goodwill during the periods presented (in thousands): Balance, January 31, 2019 $ 41,878 Increase in goodwill related to business combinations 13,606 Balance, October 31, 2019 $ 55,484
Gross carrying amount and accumulated amortization of intangible assets	The gross carrying amount and accumulated amortization of the Company’s intangible assets are as follows (in thousands): October 31, 2019 Gross Carrying Value Accumulated Amortization Net Book Value Developed technology $ 34,700 $ (10,058 ) $ 24,642 Domain name 155 (145 ) 10 Customer relationships 15,200 (2,870 ) 12,330 Total $ 50,055 $ (13,073 ) $ 36,982 January 31, 2019 Gross Carrying Value Accumulated Amortization Net Book Value Developed technology $ 7,400 $ (4,358 ) $ 3,042 Domain name 155 (128 ) 27 Customer relationships 13,500 (675 ) 12,825 Total $ 21,055 $ (5,161 ) $ 15,894
Future amortization expense related to intangible assets	As of October 31, 2019 , future amortization expense related to the intangible assets is as follows (in thousands): Years Ending January 31, Remainder of 2020 $ 2,202 2021 8,504 2022 8,500 2023 8,500 2024 7,825 2025 1,451 Total $ 36,982

Convertible Senior Notes (Table

Convertible Senior Notes (Tables)	9 Months Ended
	Oct. 31, 2019
Debt Disclosure [Abstract]
Convertible debt schedules	The net carrying amount of the liability component of the Notes was as follows (in thousands): October 31, 2019 Principal $ 300,000 Unamortized debt discount (67,964 ) Unamortized debt issuance costs (5,346 ) Net carrying amount $ 226,690 The net carrying amount of the equity component of the Notes was as follows (in thousands): October 31, 2019 Debt discount for conversion option $ 84,168 Issuance costs (2,485 ) Net carrying amount $ 81,683
Interest expense related to Notes	The following table sets forth the interest expense related to the Notes (in thousands): Three Months Ended October 31, Nine Months Ended October 31, 2019 2018 2019 2018 Contractual interest expense $ 563 $ 563 $ 1,688 $ 763 Amortization of debt discount 3,132 2,938 9,248 3,971 Amortization of issuance costs 202 174 585 234 Total $ 3,897 $ 3,675 $ 11,521 $ 4,968

Leases (Tables)

Leases (Tables)	9 Months Ended
	Oct. 31, 2019
Leases [Abstract]
Lease, Cost	The following table presents supplemental information related to the Company’s finance and operating leases (in thousands, except weighted-average information): Nine Months Ended October 31, 2019 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from finance lease $ 916 Operating cash flows from operating leases 3,204 Financing cash flows from finance lease 798 Right-of-use assets obtained in exchange for lease obligations: Finance lease $ — Operating leases 3,930 Weighted-average remaining lease term (in years): Finance lease 10.2 Operating leases 4.3 Weighted-average discount rate: Finance lease 5.6 % Operating leases 6.1 % The components of the Company’s lease costs included in its condensed consolidated statement of operations were as follows (in thousands): Three Months Ended October 31, 2019 Nine Months Ended October 31, 2019 Finance lease cost: Amortization of right-of-use assets $ 994 $ 2,982 Interest on lease liabilities 916 2,739 Operating lease cost 1,152 3,505 Short-term lease cost 785 1,488 Total lease cost $ 3,847 $ 10,714
Assets And Liabilities, Lessee	The balances of the Company’s finance and operating leases were recorded on the condensed consolidated balance sheet as follows (in thousands): October 31, 2019 Finance Lease: Property and equipment, net $ 40,405 Other accrued liabilities 4,568 Other liabilities, non-current 60,439 Operating Leases: Operating lease right-of-use assets $ 12,151 Operating lease liabilities (current) 4,180 Operating lease liabilities, non-current 9,044
Finance Lease, Liability, Maturity	Future minimum lease payments under non-cancelable finance and operating leases on an annual undiscounted cash flow basis as of October 31, 2019 were as follows (in thousands): Year Ending January 31, Finance Lease Operating Leases Remainder of 2020 $ 2,018 $ 1,634 2021 8,073 5,163 2022 8,073 2,957 2023 8,073 2,730 2024 8,073 1,276 Thereafter 51,274 2,254 Total minimum payments 85,584 16,014 Less imputed interest (20,577 ) (2,790 ) Present value of future minimum lease payments 65,007 13,224 Less current obligations under leases (4,568 ) (4,180 ) Non-current lease obligations $ 60,439 $ 9,044
Lessee, Operating Lease, Liability, Maturity	Future minimum lease payments under non-cancelable finance and operating leases on an annual undiscounted cash flow basis as of October 31, 2019 were as follows (in thousands): Year Ending January 31, Finance Lease Operating Leases Remainder of 2020 $ 2,018 $ 1,634 2021 8,073 5,163 2022 8,073 2,957 2023 8,073 2,730 2024 8,073 1,276 Thereafter 51,274 2,254 Total minimum payments 85,584 16,014 Less imputed interest (20,577 ) (2,790 ) Present value of future minimum lease payments 65,007 13,224 Less current obligations under leases (4,568 ) (4,180 ) Non-current lease obligations $ 60,439 $ 9,044
Schedule of Future Minimum Lease Payments for Capital Leases	Future minimum lease payments under non-cancelable financing and operating leases, based on the previous lease accounting standard, as of January 31, 2019, were as follows (in thousands): Year Ending January 31, Financing Lease Operating Leases 2020 $ 3,732 $ 4,578 2021 8,073 3,765 2022 8,073 2,277 2023 8,073 2,224 2024 8,073 922 Thereafter 51,274 2,149 Total minimum payments $ 87,298 $ 15,915
Schedule of Future Minimum Rental Payments for Operating Leases	Future minimum lease payments under non-cancelable financing and operating leases, based on the previous lease accounting standard, as of January 31, 2019, were as follows (in thousands): Year Ending January 31, Financing Lease Operating Leases 2020 $ 3,732 $ 4,578 2021 8,073 3,765 2022 8,073 2,277 2023 8,073 2,224 2024 8,073 922 Thereafter 51,274 2,149 Total minimum payments $ 87,298 $ 15,915

Revenue (Tables)

Revenue (Tables)	9 Months Ended
	Oct. 31, 2019
Revenues [Abstract]
Schedule of total revenue by geographic areas	The following table presents the Company’s revenues disaggregated by primary geographical markets, subscription product categories and services (in thousands): Three Months Ended October 31, Nine Months Ended October 31, 2019 2018 2019 2018 Primary geographical markets: Americas $ 71,332 $ 43,570 $ 194,055 $ 115,726 EMEA 30,374 24,406 83,504 56,367 Asia Pacific 7,735 3,806 20,638 9,439 Total $ 109,441 $ 71,782 $ 298,197 $ 181,532 Subscription product categories and services: MongoDB Atlas-related $ 44,133 $ 15,375 $ 111,783 $ 32,945 Other subscription 59,694 51,229 170,194 134,814 Services 5,614 5,178 16,220 13,773 Total $ 109,441 $ 71,782 $ 298,197 $ 181,532

Equity Incentive Plans and Em_2

Equity Incentive Plans and Employee Stock Purchase Plan (Tables)	9 Months Ended
	Oct. 31, 2019
Share-based Payment Arrangement [Abstract]
Schedule of stock option activity	The following table summarizes stock option activity for the nine months ended October 31, 2019 (in thousands, except share and per share data and years): Shares Weighted- Weighted- Aggregate Balance - January 31, 2019 8,621,010 $ 7.75 6.7 $ 729,392 Stock options exercised (1,729,833 ) 7.67 Stock options forfeited and expired (208,258 ) 11.56 Balance - October 31, 2019 6,682,919 $ 7.66 5.9 $ 802,710 Vested and exercisable - January 31, 2019 5,342,183 $ 6.95 6.0 $ 456,275 Vested and exercisable - October 31, 2019 4,790,453 $ 7.07 5.5 $ 578,198
Schedule of restricted stock unit activity	The following table summarizes RSU activity for the nine months ended October 31, 2019 : Shares Weighted-Average Grant Date Fair Value per RSU Unvested - January 31, 2019 1,988,774 $ 54.22 RSUs granted 1,530,227 118.47 RSUs vested (541,132 ) 62.07 RSUs forfeited and canceled (212,881 ) 78.30 Unvested - October 31, 2019 2,764,988 $ 86.38
Schedule of stock-based compensation expense recognized in consolidated statements of operations	Total stock-based compensation expense recognized in the Company’s unaudited condensed consolidated statements of operations is as follows (in thousands): Three Months Ended October 31, Nine Months Ended October 31, 2019 2018 2019 2018 Cost of revenue—subscription $ 1,274 $ 555 $ 3,476 $ 1,403 Cost of revenue—services 793 335 2107 800 Sales and marketing 6,844 3,090 17,728 7,437 Research and development 6,879 3,131 17,513 8,241 General and administrative 3,577 3,153 10,214 8,969 Total stock-based compensation expense $ 19,367 $ 10,264 $ 51,038 $ 26,850

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	9 Months Ended
	Oct. 31, 2019
Earnings Per Share [Abstract]
Schedule of basic and diluted earnings (loss) per share	The following table sets forth the computation of basic and diluted net loss per share (in thousands, except share and per share data): Three Months Ended October 31, Nine Months Ended October 31, 2019 2018 2019 2018 Numerator: Net loss $ (42,383 ) $ (22,487 ) $ (112,959 ) $ (76,824 ) Denominator: Weighted-average shares used to compute net loss per share, basic and diluted 56,411,779 52,702,526 55,600,484 51,431,021 Net loss per share, basic and diluted $ (0.75 ) $ (0.43 ) $ (2.03 ) $ (1.49 )
Schedule of antidilutive securities excluded from computation of earnings per share	The following weighted-average outstanding potentially dilutive shares of common stock were excluded from the computation of diluted net loss per share for the periods presented because the impact of including them would have been anti-dilutive. Three Months Ended October 31, Nine Months Ended October 31, 2019 2018 2019 2018 Stock options to purchase Class A common stock 2,042,636 3,046,631 2,242,253 3,315,885 Stock options to purchase Class B common stock 4,805,226 7,137,570 5,230,288 8,136,949 Unvested restricted stock units 2,876,802 1,707,692 2,790,999 1,265,391 Early exercised stock options 22,940 94,026 33,900 146,248 Shares underlying the conversion spread in the convertible senior notes 2,171,371 215,879 2,175,450 71,960

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Details) - USD ($)	3 Months Ended		9 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2019	Oct. 31, 2018	Feb. 01, 2019	Jan. 31, 2019
Accounting Policies [Abstract]
Related party transactions	$ 0	$ 0	$ 0	$ 0
Amounts payable to or receivable from related parties	0		0			$ 0
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred rent credit	12,151,000		12,151,000			$ 0
Lease liability	$ 13,224,000		$ 13,224,000
Cumulative effect of accounting change					$ 4,103,000
Accumulated Deficit
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of accounting change					4,103,000
Accounting Standards Update 2016-19
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred rent credit					53,700,000
Deferred revenue					2,900,000
Lease liability					70,200,000
Accounting Standards Update 2016-19 | Accumulated Deficit
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of accounting change					$ 4,100,000

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Financial Assets and Liabilities (Details) - USD ($) $ in Thousands	Oct. 31, 2019	Jan. 31, 2019
Short-term investments:
Total financial assets	$ 372,743	$ 406,154
Level 1
Short-term investments:
Total financial assets	372,743	406,154
Level 2
Short-term investments:
Total financial assets	0	0
Level 3
Short-term investments:
Total financial assets	0	0
U.S. government treasury securities
Short-term investments:
Short-term investments:	274,560	318,139
U.S. government treasury securities | Level 1
Short-term investments:
Short-term investments:	274,560	318,139
U.S. government treasury securities | Level 2
Short-term investments:
Short-term investments:	0	0
U.S. government treasury securities | Level 3
Short-term investments:
Short-term investments:	0	0
Money market funds
Cash and cash equivalents:
Cash and cash equivalents:	98,183	88,015
Money market funds | Level 1
Cash and cash equivalents:
Cash and cash equivalents:	98,183	88,015
Money market funds | Level 2
Cash and cash equivalents:
Cash and cash equivalents:	0	0
Money market funds | Level 3
Cash and cash equivalents:
Cash and cash equivalents:	$ 0	$ 0

Business Combinations - Additi

Business Combinations - Additional Information (Details)	May 07, 2019USD ($)asset	Oct. 31, 2019USD ($)
Kingdom Merger Sub, Inc and Tightdb, Inc. Merger
Business Acquisition [Line Items]
Percentage of voting interests acquired	100.00%
Purchase price pursuant to the merger agreement	$ 39,000,000
Consideration transferred	$ 38,800,000
Number of acquired finite-lived intangible assets | asset	2
Goodwill expected to be tax deductible	$ 0
Goodwill resulting from deferred tax liabilities		$ 3,500,000
Acquisition-related costs		$ 600,000
Technology-Based Intangible Assets | Kingdom Merger Sub, Inc and Tightdb, Inc. Merger
Business Acquisition [Line Items]
Weighted average useful life	5 years
Customer Relationships
Business Acquisition [Line Items]
Weighted average useful life		4 years 1 month 6 days
Customer Relationships | Kingdom Merger Sub, Inc and Tightdb, Inc. Merger
Business Acquisition [Line Items]
Weighted average useful life	5 years

Business Combinations - Schedu

Business Combinations - Schedule of Purchase Price Summary (Details) - Kingdom Merger Sub, Inc and Tightdb, Inc. Merger $ in Thousands	May 07, 2019USD ($)
Business Acquisition [Line Items]
Purchase price pursuant to the merger agreement	$ 39,000
Estimated cash amount	115
Downward closing working capital adjustment	(352)
Total purchase price to be allocated	$ 38,763

Business Combinations - Sche_2

Business Combinations - Schedule of Purchase Price Allocation (Details) - USD ($) $ in Thousands	Oct. 31, 2019	May 07, 2019	Jan. 31, 2019
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill (excluding deferred tax liability impact)	$ 55,484		$ 41,878
Kingdom Merger Sub, Inc and Tightdb, Inc. Merger
Acquired Finite-Lived Intangible Assets [Line Items]
Financial and tangible assets, net		$ 43
Deferred revenue		(350)
Goodwill (excluding deferred tax liability impact)		10,070
Total purchase price		38,763
Kingdom Merger Sub, Inc and Tightdb, Inc. Merger | Technology-Based Intangible Assets
Acquired Finite-Lived Intangible Assets [Line Items]
Identifiable intangible asset		27,300
Kingdom Merger Sub, Inc and Tightdb, Inc. Merger | Customer Relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Identifiable intangible asset		$ 1,700

Goodwill and Acquired Intangi_3

Goodwill and Acquired Intangible Assets, Net - Schedule of Goodwill (Details) $ in Thousands	9 Months Ended
	Oct. 31, 2019USD ($)
Goodwill [Roll Forward]
Goodwill (beginning balance)	$ 41,878
Increase in goodwill related to business combinations	13,606
Goodwill (ending balance)	$ 55,484

Goodwill and Acquired Intangi_4

Goodwill and Acquired Intangible Assets, Net - Schedule of Intangible Assets (Details) - USD ($) $ in Thousands	Oct. 31, 2019	Jan. 31, 2019
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 50,055	$ 21,055
Accumulated Amortization	(13,073)	(5,161)
Net Book Value	36,982	15,894
Developed Technology Rights
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	34,700	7,400
Accumulated Amortization	(10,058)	(4,358)
Net Book Value	24,642	3,042
Internet Domain Names
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	155	155
Accumulated Amortization	(145)	(128)
Net Book Value	10	27
Customer Relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	15,200	13,500
Accumulated Amortization	(2,870)	(675)
Net Book Value	$ 12,330	$ 12,825

Goodwill and Acquired Intangi_5

Goodwill and Acquired Intangible Assets, Net - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Oct. 31, 2019	Oct. 31, 2019
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 3.1	$ 7.9
Developed Technology Rights
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted average useful life		4 years 6 months
Internet Domain Names
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted average useful life		4 months 24 days
Customer Relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted average useful life		4 years 1 month 6 days

Goodwill and Acquired Intangi_6

Goodwill and Acquired Intangible Assets, Net - Future Amortization Expense (Details) - USD ($) $ in Thousands	Oct. 31, 2019	Jan. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Remainder of 2020	$ 2,202
2021	8,504
2022	8,500
2023	8,500
2024	7,825
2025	1,451
Net Book Value	$ 36,982	$ 15,894

Convertible Senior Notes - Addi

Convertible Senior Notes - Additional Information (Details)	2 Months Ended	9 Months Ended
	Jul. 31, 2018USD ($)day$ / shares	Oct. 31, 2019USD ($)day$ / shares	Oct. 31, 2018USD ($)	Jun. 30, 2018USD ($)
Debt Instrument [Line Items]
Proceeds from borrowings on convertible senior notes, net of issuance costs	$ 291,100,000	$ 0	$ 291,145,000
Convertible debt, conversion ratio	14.6738
Convertible debt, conversion ratio denominator	$ 1,000
Initial conversion price (in dollars per share) | $ / shares	$ 68.15	$ 68.15
Consecutive threshold trading days | day	30	30
Threshold percentage of stock price trigger	130.00%	130.00%
Carrying amount of convertible debt equity component	$ 84,200,000
Fair value of convertible debt		$ 570,000,000
Minimum
Debt Instrument [Line Items]
Threshold trading days | day	20	20
Redemption Period 1
Debt Instrument [Line Items]
Consecutive threshold trading days | day	30
Threshold percentage of stock price trigger	130.00%
Redemption Period 1 | Minimum
Debt Instrument [Line Items]
Threshold trading days | day	20
Redemption Period 2
Debt Instrument [Line Items]
Convertible debt, conversion ratio denominator	$ 1,000
Threshold trading days | day	5
Consecutive threshold trading days | day	5
Redemption Period 2 | Maximum
Debt Instrument [Line Items]
Trading price as a percentage of stock price and debt conversion rate	98.00%
Convertible Debt
Debt Instrument [Line Items]
Face amount of debt	$ 50,000,000			$ 250,000,000
Interest rate	0.75%			0.75%
Convertible debt, conversion ratio denominator		$ 100
Percentage of principal amount redeemed	100.00%
Debt issuance costs	$ 8,800,000
Effective interest rate	7.03%
Convertible Debt | Convertible Senior Notes, Liability Component
Debt Instrument [Line Items]
Debt issuance costs	$ 6,300,000	5,346,000
Convertible Debt | Convertible Senior Notes, Equity Component
Debt Instrument [Line Items]
Carrying amount of convertible debt equity component		84,168,000
Debt issuance costs	$ 2,500,000	$ 2,485,000

Convertible Senior Notes - Sche

Convertible Senior Notes - Schedule of Net Carrying Amount of the Liability Component of the Notes (Details) - Convertible Debt - USD ($) $ in Thousands	Oct. 31, 2019	Jul. 31, 2018
Debt Instrument [Line Items]
Unamortized debt issuance costs		$ (8,800)
Convertible Senior Notes, Liability Component
Debt Instrument [Line Items]
Principal	$ 300,000
Unamortized debt discount	(67,964)
Unamortized debt issuance costs	(5,346)	$ (6,300)
Net carrying amount	$ 226,690

Convertible Senior Notes - Sc_2

Convertible Senior Notes - Schedule of Net Carrying Amount of the Equity Component of the Notes (Details) - USD ($) $ in Thousands	Oct. 31, 2019	Jul. 31, 2018
Debt Instrument [Line Items]
Debt discount for conversion option		$ 84,200
Convertible Debt
Debt Instrument [Line Items]
Issuance costs		(8,800)
Convertible Senior Notes, Equity Component | Convertible Debt
Debt Instrument [Line Items]
Debt discount for conversion option	$ 84,168
Issuance costs	(2,485)	$ (2,500)
Net carrying amount	$ 81,683

Convertible Senior Notes - Sc_3

Convertible Senior Notes - Schedule of Interest Expense for the Notes (Details) - Convertible Debt - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2019	Oct. 31, 2018
Debt Instrument [Line Items]
Contractual interest expense	$ 563	$ 563	$ 1,688	$ 763
Amortization of debt discount	3,132	2,938	9,248	3,971
Amortization of issuance costs	202	174	585	234
Total	$ 3,897	$ 3,675	$ 11,521	$ 4,968

Convertible Senior Notes - Capp

Convertible Senior Notes - Capped Calls (Details) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions	2 Months Ended	3 Months Ended
	Jul. 31, 2018	Jul. 31, 2018
Option Indexed to Issuer's Equity [Line Items]
Purchase of capped calls	$ 37,100	$ 37,086
Capped Calls
Option Indexed to Issuer's Equity [Line Items]
Strike price (in dollars per share)	$ 68.15
Cap price (in dollars per share)	$ 106.90
Capped Calls | Class A Common Stock
Option Indexed to Issuer's Equity [Line Items]
Underlying capped calls (in shares)	4.4

Leases - Narrative (Details)

Leases - Narrative (Details) $ in Thousands	9 Months Ended
	Oct. 31, 2019USD ($)ft²
Leases [Abstract]
Rentable office space (in sqft) | ft²	106,230
Term of contract	12 years
Lessee, Lease, Description [Line Items]
Total minimum payments	$ 85,584
Option to extend	P5Y
Area of leased space (in sq ft) | ft²	21,000
Lease not yet commenced, estimated base rent payments	$ 8,100
NY Office Lease
Lessee, Lease, Description [Line Items]
Total minimum payments	$ 87,300

Leases - Components of Lease Ex

Leases - Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Oct. 31, 2019	Oct. 31, 2019	Oct. 31, 2018
Finance lease cost:
Amortization of right-of-use assets	$ 994	$ 2,982	$ 0
Interest on lease liabilities	916	2,739
Operating lease cost	1,152	3,505
Short-term lease cost	785	1,488
Total lease cost	$ 3,847	$ 10,714

Leases - Balance Sheet Componen

Leases - Balance Sheet Components (Details) - USD ($) $ in Thousands	Oct. 31, 2019	Jan. 31, 2019
Finance Lease:
Property and equipment, net	$ 40,405
Other accrued liabilities	4,568
Other liabilities, non-current	60,439
Operating Leases:
Operating lease right-of-use assets	12,151	$ 0
Operating lease liabilities (current)	4,180	0
Operating lease liabilities, non-current	$ 9,044	$ 0

Leases - Supplemental Informati

Leases - Supplemental Information (Details) - USD ($) $ in Thousands	9 Months Ended
	Oct. 31, 2019	Oct. 31, 2018
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from finance lease	$ 916
Operating cash flows from operating leases	3,204
Financing cash flows from finance lease	798	$ 0
Right-of-use assets obtained in exchange for lease obligations:
Finance lease	0
Operating leases	$ 3,930
Weighted-average remaining lease term (in years):
Finance lease	10 years 2 months 12 days
Operating leases	4 years 3 months 18 days
Weighted-average discount rate:
Finance lease	5.60%
Operating leases	6.10%

Leases - Lease Maturities (Deta

Leases - Lease Maturities (Details) - USD ($) $ in Thousands	Oct. 31, 2019	Jan. 31, 2019
Finance Lease, Liability, Payment, Due [Abstract]
Remainder of 2020	$ 2,018
2021	8,073
2022	8,073
2023	8,073
2024	8,073
Thereafter	51,274
Total minimum payments	85,584
Less imputed interest	(20,577)
Present value of future minimum lease payments	65,007
Less current obligations under leases	(4,568)
Non-current lease obligations	60,439
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
Remainder of 2020	1,634
2021	5,163
2022	2,957
2023	2,730
2024	1,276
Thereafter	2,254
Total minimum payments	16,014
Less imputed interest	(2,790)
Present value of future minimum lease payments	13,224
Less current obligations under leases	(4,180)	$ 0
Non-current lease obligations	$ 9,044	$ 0

Leases - Lease Maturities Prior

Leases - Lease Maturities Prior To Adoption of New Lease Standard (Details) $ in Thousands	Jan. 31, 2019USD ($)
Financing Lease
2020	$ 3,732
2021	8,073
2022	8,073
2023	8,073
2024	8,073
Thereafter	51,274
Total minimum payments	87,298
Operating Leases
2020	4,578
2021	3,765
2022	2,277
2023	2,224
2024	922
Thereafter	2,149
Total minimum payments	$ 15,915

Commitments and Contingencies (

Commitments and Contingencies (Details) - USD ($)	Oct. 31, 2019	Jan. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Accrual for contingencies	$ 0	$ 0

Revenue - Schedule of total rev

Revenue - Schedule of total revenue by geographic areas (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2019	Oct. 31, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	$ 109,441	$ 71,782	$ 298,197	$ 181,532
MongoDB Atlas-related
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	44,133	15,375	111,783	32,945
Other subscription
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	59,694	51,229	170,194	134,814
Services
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	5,614	5,178	16,220	13,773
Americas
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	71,332	43,570	194,055	115,726
Europe, Middle East and Africa
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	30,374	24,406	83,504	56,367
Asia Pacific
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	$ 7,735	$ 3,806	$ 20,638	$ 9,439

Revenue - Concentration Risk (D

Revenue - Concentration Risk (Details) - Geographic Concentration Risk - Revenue, Net	3 Months Ended		9 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2019	Oct. 31, 2018
United States
Concentration Risk [Line Items]
Concentration risk, percentage	61.00%	57.00%	60.00%	60.00%
United Kingdom
Concentration Risk [Line Items]
Concentration risk, percentage	9.00%	10.00%	10.00%	10.00%

Revenue - Additional Informatio

Revenue - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2019	Oct. 31, 2018	Jan. 31, 2019
Revenues [Abstract]
Deferred revenue	$ 152,400,000		$ 152,400,000		$ 137,700,000
Revenue recognized			109,600,000	$ 73,500,000
Remaining performance obligation	187,800,000		187,800,000
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Unbilled receivables	9,000,000		9,000,000
Deferred commissions	60,800,000		60,800,000
Amortization of deferred commissions	4,900,000	$ 3,600,000	13,900,000	10,200,000
Impairment loss	$ 0	$ 0	$ 0	$ 0
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-11-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation, percentage	53.00%		53.00%
Expected timing of satisfaction of remaining performance obligation	12 months		12 months

Equity Incentive Plans and Em_3

Equity Incentive Plans and Employee Stock Purchase Plan - Stock Options (Details) - Employee Stock Option	9 Months Ended
	Oct. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	4 years
One Year Anniversary
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting rights percentage	25.00%
13 to 36 Months
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting rights percentage	75.00%

Equity Incentive Plans and Em_4

Equity Incentive Plans and Employee Stock Purchase Plan - Schedule of Stock Option Activity (Details) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Oct. 31, 2019USD ($)$ / sharesshares	Jan. 31, 2019USD ($)$ / sharesshares
Shares
Balance - beginning of period (in shares) | shares	8,621,010
Stock options exercised (in shares) | shares	(1,729,833)
Stock options forfeited and expired (in shares) | shares	(208,258)
Balance - end of period (in shares) | shares	6,682,919	8,621,010
Vested and exercisable (in shares) | shares	4,790,453	5,342,183
Weighted- Average Exercise Price Per Share
Balance - beginning of period (in dollars per share) | $ / shares	$ 7.75
Stock options exercised (in dollars per share) | $ / shares	7.67
Stock options forfeited and expired (in dollars per share) | $ / shares	11.56
Balance - end of period (in dollars per share) | $ / shares	7.66	$ 7.75
Vested and exercisable (in dollars per share) | $ / shares	$ 7.07	$ 6.95
Weighted- Average Remaining Contractual Term (In Years)
Balance	5 years 10 months 24 days	6 years 8 months 12 days
Vested and exercisable	5 years 6 months	6 years
Aggregate Intrinsic Value
Balance | $	$ 802,710	$ 729,392
Vested and exercisable | $	$ 578,198	$ 456,275

Equity Incentive Plans and Em_5

Equity Incentive Plans and Employee Stock Purchase Plan - Restricted Stock Units, Additional Information (Details) - Restricted Stock Units (RSUs)	9 Months Ended
	Oct. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	4 years
One Year Anniversary
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	4 years
Vesting rights percentage	25.00%
13 to 36 Months
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting rights percentage	75.00%

Equity Incentive Plans and Em_6

Equity Incentive Plans and Employee Stock Purchase Plan - Schedule of Restricted Stock Unit Activity (Details) - Restricted Stock Units (RSUs)	9 Months Ended
	Oct. 31, 2019$ / sharesshares
Shares
Unvested - beginning of period (in shares) | shares	1,988,774
RSUs granted (in shares) | shares	1,530,227
RSUs vested (in shares) | shares	(541,132)
RSUs forfeited and canceled (in shares) | shares	(212,881)
Unvested - end of period (in shares) | shares	2,764,988
Weighted-Average Grant Date Fair Value per RSU
Unvested - beginning of period (in dollars per share) | $ / shares	$ 54.22
RSUs granted (in dollars per share) | $ / shares	118.47
RSUs vested (in dollars per share) | $ / shares	62.07
RSUs forfeited and canceled (in dollars per share) | $ / shares	78.30
Unvested - end of period (in dollars per share) | $ / shares	$ 86.38

Equity Incentive Plans and Em_7

Equity Incentive Plans and Employee Stock Purchase Plan - Employee Stock Purchase Plan, Additional Information (Details) - Employee Stock Purchase Plan shares in Millions	Oct. 31, 2019shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)	2
Maximum employee contribution rate	15.00%

Equity Incentive Plans and Em_8

Equity Incentive Plans and Employee Stock Purchase Plan - Stock-based Compensation Expense Recognized in Statement of Operations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2019	Oct. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 19,367	$ 10,264	$ 51,038	$ 26,850
Cost of revenue—subscription
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	1,274	555	3,476	1,403
Cost of revenue—services
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	793	335	2,107	800
Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	6,844	3,090	17,728	7,437
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	6,879	3,131	17,513	8,241
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 3,577	$ 3,153	$ 10,214	$ 8,969

Net Loss Per Share - Additional

Net Loss Per Share - Additional Information (Details)	3 Months Ended	9 Months Ended
	Oct. 31, 2019$ / sharesshares	Oct. 31, 2019shares$ / shares	Jul. 31, 2018$ / shares
Class of Stock [Line Items]
Shares issuable upon conversion (in shares)	4,400,000	4,400,000
Initial conversion price (in dollars per share) | $ / shares	$ 68.15	$ 68.15	$ 68.15
Average market price (in dollars per share) | $ / shares	$ 134.49
Class A Common Stock
Class of Stock [Line Items]
Number of votes per share		1
Class B Common Stock
Class of Stock [Line Items]
Number of votes per share		10

Net Loss Per Share - Schedule o

Net Loss Per Share - Schedule of Basic and Diluted Earnings (Loss) Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Oct. 31, 2019	Jul. 31, 2019	Apr. 30, 2019	Oct. 31, 2018	Jul. 31, 2018	Apr. 30, 2018	Oct. 31, 2019	Oct. 31, 2018
Numerator:
Net loss	$ (42,383)	$ (37,336)	$ (33,240)	$ (22,487)	$ (27,782)	$ (26,555)	$ (112,959)	$ (76,824)
Denominator:
Weighted-average shares used to compute net loss per share, basic and diluted (in shares)	56,411,779			52,702,526			55,600,484	51,431,021
Net loss per share, basic and diluted (in dollars per share)	$ (0.75)			$ (0.43)			$ (2.03)	$ (1.49)

Net Loss Per Share - Schedule_2

Net Loss Per Share - Schedule of Antidilutive Securities Excluded from the Computation of Diluted Net Loss per Share (Details) - shares	3 Months Ended		9 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2019	Oct. 31, 2018
Stock options to purchase common stock | Class A Common Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	2,042,636	3,046,631	2,242,253	3,315,885
Stock options to purchase common stock | Class B Common Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	4,805,226	7,137,570	5,230,288	8,136,949
Unvested restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	2,876,802	1,707,692	2,790,999	1,265,391
Early exercised stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	22,940	94,026	33,900	146,248
Shares underlying the conversion spread in the convertible senior notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	2,171,371	215,879	2,175,450	71,960

Income Taxes (Details)

Income Taxes (Details) - USD ($)	3 Months Ended		9 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2019	Oct. 31, 2018
Income Tax Disclosure [Abstract]
Provision (benefit) for income taxes	$ 559,000	$ (33,000)	$ (2,920,000)	$ 680,000
Valuation allowance			3,500,000
Unrecognized tax benefits	4,600,000		4,600,000
Unrecognized tax benefits that would impact effective tax rate	100,000		100,000
Decrease in unrecognized tax benefits is reasonably possible	$ 0		$ 0

Uncategorized Items - mdb-10311

Label	Element	Value
Restricted Cash and Cash Equivalents, Noncurrent	us-gaap_RestrictedCashAndCashEquivalentsNoncurrent	$ 515,000
Restricted Cash and Cash Equivalents, Noncurrent	us-gaap_RestrictedCashAndCashEquivalentsNoncurrent	$ 515,000