Vertex (VERX) 10-Q 6 Nov 24 2024 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2024	Nov. 01, 2024
Document Information:
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2024
Document Transition Report	false
Entity File Number	001-39413
Entity Registrant Name	Vertex, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	23-2081753
Entity Address, Address Line One	2301 Renaissance Blvd
Entity Address, City or Town	King of Prussia
Entity Address State Or Province	PA
Entity Address, Postal Zip Code	19406
City Area Code	800
Local Phone Number	355-3500
Title of 12(b) Security	Class A Common Stock, Par Value $0.001 Per Share
Trading Symbol	VERX
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	0001806837
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q3
Amendment Flag	false
Class A
Document Information:
Entity Common Stock, Shares Outstanding		65,969,319
Class B
Document Information:
Entity Common Stock, Shares Outstanding		89,990,641

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 278,979	$ 68,175
Funds held for customers	26,407	20,976
Accounts receivable, net of allowance of $14,273 and $16,272, respectively	129,908	141,752
Prepaid expenses and other current assets	33,863	26,173
Investment securities available-for-sale, at fair value (amortized cost of $7,434 and $9,550, respectively)	7,462	9,545
Total current assets	476,619	266,621
Property and equipment, net of accumulated depreciation	178,578	100,734
Capitalized software, net of accumulated amortization	36,864	38,771
Goodwill and other intangible assets	388,716	260,238
Deferred commissions	22,540	21,237
Deferred income tax asset	61,193	41,708
Operating lease right-of-use assets	12,567	14,605
Other assets	13,763	16,013
Total assets	1,190,840	759,927
Current liabilities:
Current portion of long-term debt		2,500
Accounts payable	29,229	23,596
Accrued expenses	44,643	44,735
Customer funds obligations	23,762	17,731
Accrued salaries and benefits	20,025	12,277
Accrued variable compensation	35,391	34,105
Deferred revenue, current	300,620	290,143
Current portion of operating lease liabilities	3,863	3,717
Current portion of finance lease liabilities	88	74
Purchase commitment and contingent consideration liabilities, current	300	11,901
Total current liabilities	457,921	440,779
Deferred revenue, net of current portion	3,792	2,577
Debt, net of current portion	334,656	44,059
Operating lease liabilities, net of current portion	13,568	16,567
Finance lease liabilities, net of current portion	20	51
Purchase commitment and contingent consideration liabilities, net of current portion	105,000	2,600
Deferred income tax liabilities	16,187
Deferred other liabilities	670	313
Total liabilities	931,814	506,946
Commitments and contingencies (Note 12)
Stockholders' equity:
Preferred shares, $0.001 par value, 30,000 shares authorized; no shares issued and outstanding
Additional paid in capital	264,494	275,155
Retained earnings (Accumulated deficit)	14,483	(586)
Accumulated other comprehensive loss	(20,107)	(21,742)
Total stockholders' equity	259,026	252,981
Total liabilities and stockholders' equity	1,190,840	759,927
Class A
Stockholders' equity:
Common stock	66	61
Class B
Stockholders' equity:
Common stock	$ 90	$ 93

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Allowance for accounts receivable	$ 14,273	$ 16,272
Amortized cost	$ 7,434	$ 9,550
Preferred stock par value (per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	30,000	30,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Class A
Common stock par value (per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	300,000	300,000
Common stock, shares issued (in shares)	65,722	60,989
Common stock, shares outstanding (in shares)	65,722	60,989
Class B
Common stock par value (per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	150,000	150,000
Common stock, shares issued (in shares)	90,161	92,661
Common stock, shares outstanding (in shares)	90,161	92,661

Condensed Consolidated Statemen

Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Revenues:
Total revenues	$ 170,435	$ 145,027	$ 488,320	$ 417,473
Cost of revenues:
Total cost of revenues	59,911	56,871	179,316	162,497
Gross profit	110,524	88,156	309,004	254,976
Operating expenses:
Research and development	15,621	16,772	47,080	45,314
Selling and marketing	42,111	33,919	123,143	103,196
General and administrative	41,499	35,385	112,915	109,071
Depreciation and amortization	5,214	3,782	15,432	11,401
Other operating expense (income), net	1,183	316	(442)	1,013
Total operating expenses	105,628	90,174	298,128	269,995
Income (loss) from operations	4,896	(2,018)	10,876	(15,019)
Interest expense (income), net	(2,938)	597	(2,471)	142
Income (loss) before income taxes	7,834	(2,615)	13,347	(15,161)
Income tax (benefit) expense	613	784	(1,722)	13,266
Net income (loss)	7,221	(3,399)	15,069	(28,427)
Other comprehensive (income) loss:
Foreign currency translation adjustments, net of tax	(8,955)	5,311	(1,609)	1,580
Unrealized (gain) loss on investments, net of tax	(24)	(10)	(26)	(20)
Total other comprehensive (income) loss, net of tax	(8,979)	5,301	(1,635)	1,560
Total comprehensive income (loss)	16,200	(8,700)	16,704	(29,987)
Software subscriptions
Revenues:
Total revenues	146,254	121,285	414,527	350,135
Cost of revenues:
Total cost of revenues	43,641	41,055	131,030	116,974
Services
Revenues:
Total revenues	24,181	23,742	73,793	67,338
Cost of revenues:
Total cost of revenues	$ 16,270	$ 15,816	$ 48,286	$ 45,523
Class A
Other comprehensive (income) loss:
Net income (loss) per share, basic (in dollars per share)	$ 0.05	$ (0.02)	$ 0.10	$ (0.19)
Net income (loss) per share, diluted (in dollars per share)	0.04	(0.02)	0.09	(0.19)
Class B
Other comprehensive (income) loss:
Net income (loss) per share, basic (in dollars per share)	0.05	(0.02)	0.10	(0.19)
Net income (loss) per share, diluted (in dollars per share)	$ 0.04	$ (0.02)	$ 0.09	$ (0.19)

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Changes in Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Common Stock Class A	Common Stock Class B	Additional Paid In Capital	Retained Earnings (Accumulated Deficit)	Accumulated Other Comprehensive Loss	Class A	Class B	Total
Balance at Dec. 31, 2022	$ 50	$ 100	$ 244,820	$ 12,507	$ (27,752)			$ 229,725
Balance (in shares) at Dec. 31, 2022	50,014	100,307
Exercise of stock options, net	$ 1		1,279					1,280
Exercise of stock options, net (in shares)	592
Shares issued upon vesting of Restricted Stock Units, net			(3,471)					(3,471)
Shares issued upon vesting of Restricted Stock Units, net (in shares)	391
Stock-based compensation expense			10,938					10,938
Class B shares exchanged for Class A shares	$ 2	$ (2)
Class B shares exchanged for Class A shares (in shares)	2,589	(2,589)
Foreign currency translation adjustments and revaluations, net of tax					3,122			3,122
Unrealized gain (loss) from available-for-sale investments, net of tax					13			13
Net income (loss)				(18,132)				(18,132)
Balance at Mar. 31, 2023	$ 53	$ 98	253,566	(5,625)	(24,617)			223,475
Balance (in shares) at Mar. 31, 2023	53,586	97,718
Balance at Dec. 31, 2022	$ 50	$ 100	244,820	12,507	(27,752)			229,725
Balance (in shares) at Dec. 31, 2022	50,014	100,307
Exercise of stock options, net (in shares)						1,595
Foreign currency translation adjustments and revaluations, net of tax								(1,580)
Unrealized gain (loss) from available-for-sale investments, net of tax								20
Net income (loss)								(28,427)
Balance at Sep. 30, 2023	$ 56	$ 97	265,251	(15,920)	(29,312)			220,172
Balance (in shares) at Sep. 30, 2023	55,825	96,839
Balance at Mar. 31, 2023	$ 53	$ 98	253,566	(5,625)	(24,617)			223,475
Balance (in shares) at Mar. 31, 2023	53,586	97,718
Exercise of stock options, net	$ 1		668					669
Exercise of stock options, net (in shares)	259
Shares issued upon vesting of Restricted Stock Units, net			(221)					(221)
Shares issued upon vesting of Restricted Stock Units, net (in shares)	22
Shares issued upon vesting of Restricted Stock Awards, net (in shares)	106
Stock-based compensation expense			6,904					6,904
Shares issued in connection with ESPP			1,178					1,178
Shares issued in connection with ESPP (shares)	81
Foreign currency translation adjustments and revaluations, net of tax					609			609
Unrealized gain (loss) from available-for-sale investments, net of tax					(3)			(3)
Net income (loss)				(6,896)				(6,896)
Balance at Jun. 30, 2023	$ 54	$ 98	262,095	(12,521)	(24,011)			225,715
Balance (in shares) at Jun. 30, 2023	54,054	97,718
Exercise of stock options, net	$ 1		(3,717)					(3,716)
Exercise of stock options, net (in shares)	744					744
Shares issued upon vesting of Restricted Stock Units, net			(508)					(508)
Shares issued upon vesting of Restricted Stock Units, net (in shares)	56
Shares issued upon vesting of Restricted Stock Awards, net			(146)					(146)
Shares issued upon vesting of Restricted Stock Awards, net (in shares)	92
Stock-based compensation expense			7,527					7,527
Class B shares exchanged for Class A shares	$ 1	$ (1)
Class B shares exchanged for Class A shares (in shares)	879	(879)
Foreign currency translation adjustments and revaluations, net of tax					(5,311)			(5,311)
Unrealized gain (loss) from available-for-sale investments, net of tax					10			10
Net income (loss)				(3,399)				(3,399)
Balance at Sep. 30, 2023	$ 56	$ 97	265,251	(15,920)	(29,312)			220,172
Balance (in shares) at Sep. 30, 2023	55,825	96,839
Balance at Dec. 31, 2023	$ 61	$ 93	275,155	(586)	(21,742)			252,981
Balance (in shares) at Dec. 31, 2023	60,989	92,661				60,989	92,661
Exercise of stock options, net			(5,454)					(5,454)
Exercise of stock options, net (in shares)	653
Shares issued upon vesting of Restricted Stock Units, net	$ 1		(10,899)					(10,898)
Shares issued upon vesting of Restricted Stock Units, net (in shares)	674
Stock-based compensation expense			14,845					14,845
Foreign currency translation adjustments and revaluations, net of tax					(4,011)			(4,011)
Unrealized gain (loss) from available-for-sale investments, net of tax					(17)			(17)
Net income (loss)				2,684				2,684
Balance at Mar. 31, 2024	$ 62	$ 93	273,647	2,098	(25,770)			250,130
Balance (in shares) at Mar. 31, 2024	62,316	92,661
Balance at Dec. 31, 2023	$ 61	$ 93	275,155	(586)	(21,742)			252,981
Balance (in shares) at Dec. 31, 2023	60,989	92,661				60,989	92,661
Exercise of stock options, net (in shares)						1,308
Foreign currency translation adjustments and revaluations, net of tax								1,609
Unrealized gain (loss) from available-for-sale investments, net of tax								26
Net income (loss)								15,069
Balance at Sep. 30, 2024	$ 66	$ 90	264,494	14,483	(20,107)			259,026
Balance (in shares) at Sep. 30, 2024	65,722	90,161				65,722	90,161
Balance at Mar. 31, 2024	$ 62	$ 93	273,647	2,098	(25,770)			250,130
Balance (in shares) at Mar. 31, 2024	62,316	92,661
Exercise of stock options, net			1,734					1,734
Exercise of stock options, net (in shares)	194
Shares issued upon vesting of Restricted Stock Units, net			(432)					(432)
Shares issued upon vesting of Restricted Stock Units, net (in shares)	32
Shares issued upon vesting of Restricted Stock Awards, net (in shares)	62
Stock-based compensation expense			9,924					9,924
Shares issued in connection with ESPP			1,443					1,443
Shares issued in connection with ESPP (shares)	61
Class B shares exchanged for Class A shares	$ 3	$ (3)
Class B shares exchanged for Class A shares (in shares)	2,500	(2,500)
Purchase of capped calls, net of tax			(31,517)					(31,517)
Foreign currency translation adjustments and revaluations, net of tax					(3,335)			(3,335)
Unrealized gain (loss) from available-for-sale investments, net of tax					19			19
Net income (loss)				5,164				5,164
Balance at Jun. 30, 2024	$ 65	$ 90	254,799	7,262	(29,086)			233,130
Balance (in shares) at Jun. 30, 2024	65,165	90,161
Exercise of stock options, net	$ 1		1,386					1,387
Exercise of stock options, net (in shares)	461					461
Shares issued upon vesting of Restricted Stock Units, net			(1,348)					(1,348)
Shares issued upon vesting of Restricted Stock Units, net (in shares)	74
Shares issued upon vesting of Restricted Stock Awards, net			(290)					(290)
Shares issued upon vesting of Restricted Stock Awards, net (in shares)	22
Stock-based compensation expense			9,946					9,946
Tax impact on capped calls			1					1
Foreign currency translation adjustments and revaluations, net of tax					8,955			8,955
Unrealized gain (loss) from available-for-sale investments, net of tax					24			24
Net income (loss)				7,221				7,221
Balance at Sep. 30, 2024	$ 66	$ 90	$ 264,494	$ 14,483	$ (20,107)			$ 259,026
Balance (in shares) at Sep. 30, 2024	65,722	90,161				65,722	90,161

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Cash flows from operating activities:
Net income (loss)	$ 15,069	$ (28,427)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	61,448	52,597
Amortization of cloud computing implementation costs	2,994	1,550
Provision for subscription cancellations and non-renewals	(470)	1,407
Amortization of deferred financing costs	1,345	189
Change in fair value of contingent consideration liabilities	(2,275)	1,349
Change in settlement value of deferred purchase commitment liability	423
Write-off of deferred financing costs	276
Stock-based compensation expense	36,459	26,228
Deferred income tax benefit	(8,615)	(10,034)
Non-cash operating lease costs	2,038	1,855
Other	(151)	(145)
Changes in operating assets and liabilities:
Accounts receivable	15,593	(30,760)
Prepaid expenses and other current assets	(10,245)	520
Deferred commissions	(1,302)	(1,632)
Accounts payable	4,535	10,049
Accrued expenses	(851)	9,865
Accrued and deferred compensation	3,032	2,487
Deferred revenue	9,411	(8,977)
Operating lease liabilities	(2,856)	(2,863)
Payments for purchase commitment and contingent consideration liabilities in excess of initial fair value	(4,367)
Other	2,197	1,438
Net cash provided by operating activities	123,688	26,696
Cash flows from investing activities:
Acquisition of businesses and assets, net of cash acquired	(71,755)
Property and equipment additions	(47,520)	(35,357)
Capitalized software additions	(16,357)	(14,083)
Purchase of investment securities, available-for-sale	(12,246)	(12,864)
Proceeds from sales and maturities of investment securities, available-for-sale	14,610	16,040
Net cash used in investing activities	(133,268)	(46,264)
Cash flows from financing activities:
Net increase in customer funds obligations	6,032	16,996
Proceeds from convertible senior notes	345,000
Principal payments on long-term debt	(46,875)	(1,563)
Payments on third-party debt	(3,904)
Payment for purchase of capped calls	(42,366)
Payments for deferred financing costs	(11,374)
Proceeds from purchases of stock under ESPP	1,443	1,178
Payments for taxes related to net share settlement of stock-based awards	(19,990)	(9,210)
Proceeds from exercise of stock options	4,689	3,097
Payments for purchase commitment and contingent consideration liabilities	(7,580)	(6,424)
Payments of finance lease liabilities	(70)	(77)
Payments for deferred purchase commitments		(10,000)
Net cash provided by (used in) financing activities	225,005	(6,003)
Effect of exchange rate changes on cash, cash equivalents and restricted cash	810	(55)
Net increase (decrease) in cash, cash equivalents and restricted cash	216,235	(25,626)
Cash, cash equivalents and restricted cash, beginning of period	89,151	106,748
Cash, cash equivalents and restricted cash, end of period	$ 305,386	$ 81,122

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2024	Sep. 30, 2023
Reconciliation of cash, cash equivalents and restricted cash to the Condensed Consolidated Balance Sheets, end of period:
Cash and cash equivalents	$ 278,979	$ 49,499
Restricted cash-funds held for customers	26,407	31,623
Total cash, cash equivalents and restricted cash, end of period	$ 305,386	$ 81,122

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	9 Months Ended
	Sep. 30, 2024
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	1. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Nature of Business Vertex, Inc. (“Vertex”) and its consolidated subsidiaries and variable interest entities (“VIE”) (collectively, the “Company”) operate as solutions providers of state, local, and value added tax calculation, compliance, and analytics, offering software products that are sold through software license and software as a service (“cloud”) subscriptions. The Company also provides implementation and training services in connection with its software license and cloud subscriptions, transaction tax returns outsourcing, and other tax-related services. The Company sells to customers located throughout the United States of America (“U.S.”) and internationally. Basis of Consolidation The condensed consolidated financial statements are prepared in accordance with accounting principles generally accepted in the U.S. (“U.S. GAAP”) and include the accounts of the Company. All intercompany transactions have been eliminated in consolidation. On August 30, 2024, the Company completed its acquisition of ecosio GmbH (“ecosio”). Upon its acquisition, ecosio became a wholly owned subsidiary of the Company, and its operations have been included in the Company’s condensed consolidated financial statements commencing on the acquisition date. ​ Prior to June 5, 2024, the Company owned an 80% controlling equity interest in Systax Sistemas Fiscais LTDA (“Systax”), a provider of Brazilian transaction tax content and software. Systax was determined to be a VIE and the accounts were included in the condensed consolidated financial statements. Vertex did not have full decision-making authority over Systax; however, Vertex was the entity that most significantly participated in the variability of the fair value of Systax’s net assets and was considered the entity most closely associated to Systax. As such, Vertex was deemed the primary beneficiary of Systax and consolidated Systax into its condensed consolidated financial statements. On June 5, 2024, Vertex acquired the remaining 20% equity interest in Systax. Systax is now a wholly owned subsidiary of the Company and is consolidated into the condensed consolidated financial statements. Unaudited Interim Financial Information The accompanying unaudited interim condensed consolidated financial statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”) for interim financial information and include the accounts of the Company. Certain information and disclosures normally included in consolidated financial statements prepared in accordance with U.S. GAAP have been condensed or omitted. Accordingly, these interim condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and the related notes for the year ended December 31, 2023 included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2023 (the “2023 Annual Report”) filed with the SEC on February 29, 2024. The condensed consolidated balance sheet as of December 31, 2023 has been derived from audited financial statements included in the 2023 Annual Report. The accompanying interim condensed consolidated balance sheet as of September 30, 2024, the interim condensed consolidated statements of comprehensive income (loss) and changes in stockholders’ equity for the three and nine months ended September 30, 2024 and 2023, and the interim condensed consolidated statements of cash flows for the nine months ended September 30, 2024 and 2023 are unaudited. The unaudited interim condensed consolidated financial statements have been prepared on a basis consistent with that used to prepare the annual audited consolidated financial statements and include, in the opinion of management, all adjustments, consisting of normal and recurring items necessary for the fair presentation of the condensed consolidated financial statements. The operating results for the three and nine months ended September 30, 2024 are not necessarily indicative of the results expected for the full year ending December 31, 2024. ​ Segments The Company operates its business as one operating segment. For the three and nine months ended September 30, 2024, approximately 8% and 7%, respectively, of the Company’s revenues were generated from customers located outside the U.S. For both the three and nine months ended September 30, 2023, approximately 7% of the Company’s revenues were generated from customers located outside the U.S. As of September 30, 2024 and December 31, 2023, $654 and $633, respectively, of the Company’s tangible property and equipment assets were held outside the U.S. ​ Use of Estimates The preparation of condensed consolidated financial statements requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, equity, revenues, and expenses during the reporting period. Significant estimates used in preparing these condensed consolidated financial statements include: (i) the estimated allowance for subscription cancellations; (ii) expected credit losses associated with the allowance for doubtful accounts; (iii) allowance for credit losses on available-for-sale debt securities; (iv) the reserve for self-insurance; (v) assumptions related to achievement of technological feasibility for software developed for sale; (vi) product life cycles; (vii) estimated useful lives and potential impairment of long-lived assets, intangible assets, and capitalized cloud computing arrangement (“CCA”) software implementation costs; (viii) potential impairment of goodwill; (ix) determination of the fair value of tangible and intangible assets acquired, liabilities assumed, and consideration transferred in acquisitions; (x) amortization period of deferred commissions; (xi) Black-Scholes-Merton option pricing model (“Black-Scholes model”) input assumptions used to determine the fair value of certain stock-based compensation awards and Employee Stock Purchase Plan (“ESPP”) purchase rights; (xii) measurement of future purchase commitment, fair value of contingent consideration liabilities related to cash and stock earn-out payments, and deferred purchase consideration liabilities associated with acquisitions; and (xiii) the potential outcome of future tax consequences of events that have been recognized in the condensed consolidated financial statements or tax returns. Actual results may differ from these estimates. ​ ​ Convertible Senior Notes The Company accounts for its convertible senior notes (the “Notes”) wholly as debt under ASU 2026-06 Debt—Debt with Conversion and Other Options (Subtopic 470-20.) ​ Capped Call Transactions ​ Derivatives and Hedging Supplemental Balance Sheet Disclosures Supplemental balance sheet disclosures are as follows for the respective periods: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of September 30, ​ ​ As of December 31, ​ 2024 ​ 2023 ​ (unaudited) ​ ​ ​ Prepaid expenses and other current assets: ​ ​ Prepaid expenses ​ $ 12,534 ​ $ 11,558 Unamortized cloud computing implementation costs ​ ​ 3,995 ​ ​ 3,995 Prepaid insurance ​ ​ 995 ​ ​ 521 Prepaid licenses and support ​ ​ 16,339 ​ ​ 10,099 Prepaid expenses and other current assets ​ $ 33,863 ​ $ 26,173 ​ ​ ​ ​ ​ ​ ​ Other assets: ​ ​ ​ ​ Unamortized cloud computing implementation costs ​ $ 10,866 ​ $ 12,475 Other assets ​ ​ 2,897 ​ ​ 3,538 Total other assets ​ $ 13,763 ​ $ 16,013 ​ ​ ​ ​ ​ ​ ​ Accrued expenses: ​ ​ ​ ​ ​ ​ Accrued general expenses ​ $ 20,472 ​ $ 25,998 Accrued contract labor and professional fees ​ ​ 18,344 ​ ​ 13,372 Accrued income and other taxes ​ ​ 5,827 ​ ​ 5,365 Accrued expenses ​ $ 44,643 ​ $ 44,735 ​ ​ ​ ​ ​ ​ ​ ​ Cloud computing software implementation costs incurred in hosting arrangements are capitalized and reported as a component of prepaid expenses and other current assets, or other assets, once available for their intended use. These costs are amortized using the straight-line method over their respective contract service periods, including periods covered by an option to extend, ranging from two ​ Recently Issued or Adopted Accounting Pronouncements Segment Reporting Income Tax Disclosures ​

REVENUE RECOGNITION

REVENUE RECOGNITION	9 Months Ended
	Sep. 30, 2024
REVENUE RECOGNITION
REVENUE RECOGNITION	2. REVENUE RECOGNITION Disaggregation of revenue The table reflects revenue by major source for the following periods: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended September 30, Nine months ended September 30, ​ ​ 2024 2023 ​ 2024 2023 ​ (unaudited) (unaudited) Software subscriptions: ​ ​ ​ ​ ​ ​ ​ ​ ​ Software licenses ​ $ 75,273 ​ $ 66,637 $ 215,365 ​ $ 196,070 Cloud subscriptions ​ ​ 70,981 ​ ​ 54,648 ​ 199,162 ​ ​ 154,065 Software subscriptions ​ ​ 146,254 ​ ​ 121,285 ​ 414,527 ​ ​ 350,135 Services ​ 24,181 ​ 23,742 73,793 ​ 67,338 Total revenues ​ $ 170,435 ​ $ 145,027 ​ $ 488,320 ​ $ 417,473 ​ Contract balances Timing of revenue recognition may differ from the timing of invoicing customers. A receivable is recorded in the condensed consolidated balance sheets when customers are billed related to revenue to be collected and recognized for subscription agreements as there is an unconditional right to invoice and receive payment in the future related to these subscriptions. A receivable and related revenue may also be recorded in advance of billings to the extent services have been performed and the Company has a right under the contract to bill and collect for such performance. Subscription-based customers are generally invoiced annually at the beginning of each annual subscription period. Accounts receivable is presented net of an allowance for potentially uncollectible accounts and estimated cancellations of software license and cloud-based subscriptions (the “allowance”) of $14,273 and $16,272 at September 30, 2024 and December 31, 2023, respectively. The allowance for potentially uncollectible accounts represents future expected credit losses over the life of the receivables based on past experience, current information and forward-looking economic considerations. The beginning and ending balances of accounts receivable, net of allowance, are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the nine months ended September 30, 2024 ​ For the year ended December 31, 2023 ​ ​ (unaudited) ​ ​ ​ Balance, beginning of period ​ $ 141,752 ​ $ 102,885 Balance, end of period ​ 129,908 ​ 141,752 Increase (decrease), net ​ $ (11,844) ​ $ 38,867 ​ A contract liability is recorded as deferred revenue on the condensed consolidated balance sheets when customers are billed in advance of performance obligations being satisfied, and revenue is recognized after invoicing ratably over the subscription period. Deferred revenue is reflected net of a related deferred allowance for subscription cancellations (the “deferred allowance”) of $10,235 and $11,741 at September 30, 2024 and December 31, 2023, respectively. The deferred allowance represents the portion of the allowance for subscription cancellations associated with deferred revenue. The beginning and ending balances of and changes to the allowance and the deferred allowance are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the three months ended September 30, ​ ​ 2024 ​ 2023 ​ ​ Balance ​ Net Change Balance ​ Net Change ​ ​ (unaudited) Allowance balance, July 1, ​ $ (17,704) ​ ​ $ (14,218) ​ Allowance balance, September 30, ​ (14,273) ​ ​ (14,308) ​ Change in allowance ​ ​ ​ $ (3,431) ​ ​ ​ $ 90 Deferred allowance balance, July 1, ​ 12,753 ​ ​ 10,409 ​ Deferred allowance balance, September 30, ​ 10,235 ​ ​ 10,472 ​ Change in deferred allowance ​ ​ ​ 2,518 ​ ​ ​ (63) Net amount charged to revenues ​ ​ ​ $ (913) ​ ​ ​ $ 27 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the nine months ended September 30, ​ ​ 2024 ​ 2023 ​ ​ Balance ​ Net Change Balance ​ Net Change ​ ​ (unaudited) Allowance balance, January 1, ​ $ (16,272) ​ ​ $ (9,554) ​ Allowance balance, September 30, ​ (14,273) ​ ​ (14,308) ​ Change in allowance ​ ​ ​ $ (1,999) ​ ​ ​ $ 4,754 Deferred allowance balance, January 1, ​ 11,741 ​ ​ 7,133 ​ Deferred allowance balance, September 30, ​ 10,235 ​ ​ 10,472 ​ Change in deferred allowance ​ ​ ​ 1,506 ​ ​ ​ (3,339) Net amount charged to revenues ​ ​ ​ $ (493) ​ ​ ​ $ 1,415 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The portion of deferred revenue expected to be recognized in revenue beyond one year is included in deferred revenue, net of current portion in the condensed consolidated balance sheets. The following table provides information about the balances of and changes to deferred revenue for the following periods: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the three months ended September 30, ​ For the nine months ended September 30, ​ ​ 2024 ​ 2023 ​ 2024 ​ 2023 ​ ​ (unaudited) ​ (unaudited) Changes to deferred revenue: ​ ​ ​ ​ Beginning balance ​ $ 299,741 ​ $ 277,053 ​ $ 292,720 ​ $ 279,136 Additional amounts deferred ​ 175,106 ​ 134,789 ​ 500,012 ​ 405,152 Revenues recognized ​ (170,435) ​ (145,027) ​ (488,320) ​ (417,473) Ending balance ​ $ 304,412 ​ $ 266,815 ​ $ 304,412 ​ $ 266,815 ​ Contract costs Deferred sales commissions earned by the Company’s sales force and certain sales incentive programs and vendor referral agreements are considered incremental and recoverable costs of obtaining a contract with a customer. An asset is recognized for these incremental contract costs and reflected as deferred commissions in the condensed consolidated balance sheets. These contract costs are amortized on a straight-line basis over a period consistent with the transfer of the associated product and services to the customer, which is generally three years. Amortization of these costs are included in selling and marketing expense in the condensed consolidated statements of comprehensive income (loss). The Company periodically reviews these contract assets to determine whether events or changes in circumstances have occurred that could impact the period of benefit of these assets. There were no impairment losses recorded for the periods presented. ​ The changes to contract cost balances as of and for the following periods are: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the three months ended September 30, ​ For the nine months ended September 30, ​ ​ 2024 ​ 2023 ​ 2024 ​ 2023 ​ ​ (unaudited) ​ (unaudited) Deferred commissions: ​ ​ ​ ​ Beginning balance ​ $ 21,862 ​ $ 16,726 ​ $ 21,237 ​ $ 15,463 Additions ​ 5,024 ​ 3,839 ​ 13,793 ​ 9,437 Amortization ​ (4,346) ​ (3,471) ​ (12,490) ​ (7,806) Ending balance ​ $ 22,540 ​ $ 17,094 ​ $ 22,540 ​ $ 17,094 ​

ACQUISITIONS

ACQUISITIONS	9 Months Ended
	Sep. 30, 2024
ACQUISITIONS
ACQUISITIONS	​ 3. ACQUISITIONS ecosio GmbH   ​ ​ Total Purchase Consideration ​ Total purchase consideration for the ecosio acquisition was $169,041, net of $788 cash acquired, which was comprised of the following: ​ ​ ​ ​ ​ August 30, 2024 ​ (unaudited) Upfront cash consideration $ 64,829 Cash and Stock Earn-outs, at fair value ​ 105,000 Total $ 169,829 ​ ​ ​ The contingent consideration liabilities included in the consideration are in the form of cash (the “Cash Earn-out”), with an aggregate of up to $76,000, and stock, with an aggregate value of up to $35,000 (the “Stock Earn-out”, together with the Cash Earn-out, the “Earn-outs”), assuming 100% achievement. The Earn-outs will be based upon ecosio’s monthly software revenues meeting specified annual targets over a three-year period. The Cash Earn-out is payable annually and also contains a catch-up mechanism. The Stock Earn-out is payable annually and is settled in shares of the Company’s Class A common stock. The fair value of the Cash and Stock Earn-outs at acquisition was $71,000 and $34,000, respectively, and were measured on the Acquisition Date using a Monte Carlo simulation in a risk-neutral framework, calibrated to management’s revenue forecasts. The final payments may be adjusted depending on the actual amount, above or below the targets. The Stock Earn-out is classified as a liability on the condensed consolidated balance sheet in accordance with ASC Topic 815, “ Derivatives and Hedging ​ Fair Value of Assets Acquired and Liabilities Assumed ​ The purchase price was allocated to the net assets acquired based on management’s determination of their estimated fair values using available information as of the Acquisition Date. The excess of purchase consideration over the net assets acquired is recorded as goodwill, which primarily reflects the existence of intangible assets not recognized under U.S. GAAP such as the value of expected future synergies, the value of the assembled workforce and other market factors. The preliminary values recorded, which are reflected in the table below, will be adjusted during the measurement period as more detailed analyses are performed and further information becomes available regarding the fair values of these amounts on the Acquisition Date. ​ ​ ​ ​ ​ August 30, 2024 ​ ​ (unaudited) Cash and cash equivalents $ 788 Accounts receivable ​ 2,068 Prepaid expenses and other current assets ​ 475 Property and equipment (1) ​ 63,984 Other assets ​ 34 Goodwill (2) ​ 123,509 Other intangibles ​ 5,950 Accounts payable ​ (1,118) Third-party debt ​ (3,904) Accrued expenses ​ (5,184) Deferred revenue ​ (752) Deferred income tax ​ (16,021) Total $ 169,829 (1) ​ ​ (2) ​ ​ ​ ​ ​ ​ The fair value, valuation methodologies, estimated useful lives, and significant assumptions of the identifiable intangibles acquired in the ecosio acquisition are summarized in the table below: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ August 30, 2024 (unaudited) ecosio Identifiable Intangibles ​ Balance Sheet Location ​ ​ Fair Value ​ Valuation Methodology ​ Estimated Useful Life ​ Discount Rate ​ Developed technology ​ Property and equipment, net ​ $ 63,800 ​ Multi-period excess earnings method - income approach ​ 7 years ​ 15.5 % Trade name ​ Goodwill and other intangible assets ​ $ 1,450 ​ Relief from royalty method - income approach ​ 3 years ​ 15.5 % Customer relationships ​ Goodwill and other intangible assets ​ $ 4,500 ​ With and without method - income approach ​ 3 years ​ 15.5 % ​ Third-party experts were engaged to assist in the valuation of identifiable intangible assets and Earn-out payments as part of the acquisition. All estimates, key assumptions, and forecasts were either provided by, or reviewed by the Company. While the Company chose to utilize a third-party valuation specialist for assistance, the fair value analysis and related valuations reflect the conclusions of the Company and not those of any third-party. Any subsequent adjustments to the preliminary values not associated with determination of their fair values on the Acquisition Date will be recorded in the consolidated statements of comprehensive income (loss) in the period in which the adjustment is identified. ​ Total transaction costs associated with the acquisition were $720 and $1,637 for the three and nine months ended September 30, 2024, respectively and are recorded in other operating expense (income), net in the condensed consolidated statements of comprehensive income (loss). ​ Asset Acquisition Ryan, LLC Artificial Intelligence Tax Categorization On May 31, The Company paid $6,075 in closing consideration, which included $75 in transaction costs. The purchase agreement also includes the potential for earn-out payments and referral fees to Ryan over a five-year period. The earn-out payments will be paid annually in an amount equal to the (a) applicable percentage (ranging from 0% to 35%) multiplied by (b) new sales (excluding new sales to new customers). The referral fees will be paid annually to compensate Ryan for new customers ​ Following the guidance provided under the FASB Accounting Standards Update No. 2017-01, Clarifying the Definition of a Business,

FINANCIAL INSTRUMENTS AND FAIR

FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS	9 Months Ended
	Sep. 30, 2024
FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS
FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS	4. FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS Assets and Liabilities Measured at Fair Value on a Recurring Basis The following table summarizes the Company’s fair value for its financial assets and liabilities measured at fair value on a recurring basis: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurements Using As of September 30, 2024 (unaudited) ​ Fair Value Prices in active markets for identical assets (Level 1) Significant other observable inputs (Level 2) Significant unobservable inputs (Level 3) Money Market Funds ​ $ 249,150 ​ $ 249,150 ​ ​ — ​ ​ — Commercial Paper ​ ​ 6,451 ​ ​ — ​ ​ 6,451 ​ ​ — U.S. Treasury Securities ​ ​ 4,500 ​ ​ — ​ ​ 4,500 ​ ​ — Tellutax Contingent Consideration ​ ​ 300 ​ ​ — ​ ​ — ​ ​ 300 ecosio Cash Earn-out ​ ​ 71,000 ​ ​ — ​ ​ — ​ ​ 71,000 ecosio Stock Earn-out ​ ​ 34,000 ​ ​ — ​ ​ — ​ ​ 34,000 ​ ​ Fair Value Measurements Using As of December 31, 2023 ​ Fair Value Prices in active markets for identical assets (Level 1) Significant other observable inputs (Level 2) Significant unobservable inputs (Level 3) Money Market Funds ​ $ 53,049 ​ $ 53,049 ​ $ — ​ $ — Commercial Paper ​ ​ 7,168 ​ ​ — ​ ​ 7,168 ​ ​ — U.S. Treasury Securities ​ ​ 3,621 ​ ​ — ​ ​ 3,621 ​ ​ — Tellutax Contingent Consideration ​ ​ 4,900 ​ ​ — ​ ​ — ​ ​ 4,900 Foreign Currency Forward Contracts ​ ​ 849 ​ ​ — ​ ​ 849 ​ ​ — ​ The Company has investments in high quality, short-term money market instruments, which are issued and payable in U.S. dollars (“Money Market Funds”) and included in cash and cash equivalents on the condensed consolidated balance sheets. Fair value inputs for these investments are considered Level 1 measurements within the fair value hierarchy since Money Market Fund fair values are known and observable through daily published floating net asset values. Securities classified as available-for-sale are reported at fair value using Level 2 inputs. The Company has investments in bank and corporate issued commercial paper (“Commercial Paper”) and U.S. treasury securities (“U.S. Treasury Securities”). The Company believes that Level 2 designation is appropriate for Commercial Paper and U.S. Treasury Securities under ASC 820-10, Fair Value Measurements and Disclosures In connection with the August 2024 ecosio acquisition, the sellers are entitled to three annual Earn-outs based on ecosio’s achievement of certain monthly software revenue targets measured over an aggregate of 12 months and paid within 90 days after the relevant measurement period. The fair value of the Cash Earn-out and the Stock Earn-out were measured on the Acquisition Date using a Monte Carlo simulation in a risk-neutral framework, calibrated to management’s revenue forecasts. Additional information on the Cash Earn-out and the Stock Earn-out is presented in the following table: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash Earn-out ​ ​ Fair value Cash Earn-out/ Period (unaudited) ​ ​ At 100% Achievement ​ ​ At acquisition Year 1 - December 1, 2024 - December 1, 2025 ​ $ 16,000 ​ $ 16,700 Year 2 - December 1, 2025 - December 1, 2026 ​ ​ 25,000 ​ ​ 23,200 Year 3 - December 1, 2026 - December 1, 2027 ​ ​ 35,000 ​ ​ 31,100 Total Cash Earn-out ​ $ 76,000 ​ $ 71,000 ​ ​ ​ Maximum ​ ​ Fair value Stock Earn-out/ Period (unaudited) ​ ​ Payout ​ ​ At acquisition Year 1 - December 1, 2024 - December 1, 2025 ​ $ 12,000 ​ $ 12,200 Year 2 - December 1, 2025 - December 1, 2026 ​ ​ 12,000 ​ ​ 11,400 Year 3 - December 1, 2026 - December 1, 2027 ​ ​ 11,000 ​ ​ 10,400 Total Stock Earn-out ​ $ 35,000 ​ $ 34,000 ​ ​ ​ ​ ​ ​ ​ ​ Actual payouts are further adjusted depending on ecosio’s software revenue attainment for each of the measurement periods. ​ These Earn-outs represent recurring fair value measurements with significant unobservable inputs, which management considers to be Level 3 measurements under the fair value hierarchy. The final payments may be adjusted depending on the actual amount, above or below the target. Both the Cash Earn-out and the Stock Earn-out are recorded at fair value and are included in purchase commitment and contingent consideration liabilities, net of current portion in the condensed consolidated balance sheets. The Earn-outs will be revalued and adjusted quarterly until the end of the Earn-out period, and any fair value adjustments will be recorded in the other operating expense (income), net line of the condensed consolidated statement of income (loss). ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2024 (unaudited) Liabilities Fair Value ​ Valuation Technique ​ Unobservable Inputs ecosio Contingent Consideration - Cash Earn-out ​ $ 71,000 ​ ​ Monte Carlo Simulation ​ ​ Revenue volatility ​ 21.0 % ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue discount rate ​ 7.6 % ​ ​ ​ ​ ​ ​ ​ ​ ​ Term (in years) ​ 3.0 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ecosio Contingent Consideration - Stock Earn-out ​ $ 34,000 ​ ​ Monte Carlo Simulation ​ ​ Revenue volatility ​ 21.0 % ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue discount rate ​ 7.6 % ​ ​ ​ ​ ​ ​ ​ ​ ​ Term (in years) ​ 3.0 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ In connection with the January 2021 Tellutax LLC (“Tellutax”) acquisition, the sellers are entitled to contingent consideration if sales targets are met during a period of time following the acquisition (the “Tellutax Contingent Consideration”). The Tellutax Contingent Consideration is based on three potential earn-out payments determined by periodic revenue achievements over a thirty-month period. Such estimate represents a recurring fair value measurement with significant unobservable inputs, which management considers to be Level 3 measurements under the fair value hierarchy. The significant assumptions used in these calculations included forecasted results and the estimated likelihood for each performance scenario. The fair value of Tellutax Contingent Consideration is estimated using a Monte Carlo Simulation to compute the expected cash flows from the payments specified in the purchase agreement. Such payments have no maximum limit, but if certain targets are not met, there will be no payment for the applicable measurement period. Fair value adjustments of $100 and $(2,275) were recorded in other operating expense (income), net for the three and nine months ended September 30, 2024, respectively. Fair value adjustments of $900 and $1,349 were recorded in other operating expense (income), net for the three and nine months ended September 30, 2023, respectively. At September 30, 2024, the Tellutax Contingent Consideration of $300 is included in purchase commitment and contingent consideration liabilities, current in the condensed consolidated balance sheets. At December 31, 2023, the Tellutax Contingent Consideration of $2,300 and $2,600 is included in purchase commitment and contingent consideration liabilities, current, and purchase commitment and contingent consideration liabilities, net of current portion, respectively, in the condensed consolidated balance sheets. ​ Tellutax Contingent Consideration fair value as of September 30, 2024, and December 31, 2023 and unobservable inputs used for the Monte Carlo Simulation valuation were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2024 (unaudited) Liabilities Fair Value ​ Valuation Technique ​ Unobservable Inputs Tellutax Contingent Consideration ​ $ 300 ​ ​ Monte Carlo Simulation ​ ​ Revenue volatility ​ 50.0 % ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue discount rate ​ 20.2 % ​ ​ ​ ​ ​ ​ ​ ​ ​ Term (in years) ​ 0.6 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2023 Liability Fair Value ​ Valuation Technique ​ Unobservable Inputs Tellutax Contingent Consideration ​ $ 4,900 ​ ​ Monte Carlo Simulation ​ ​ Revenue volatility ​ 60.0 % ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue discount rate ​ 20.8 % ​ ​ ​ ​ ​ ​ ​ ​ ​ Term (in years) ​ 1.3 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Changes in the fair value of the Company’s level 3 liabilities during the nine months ended September 30, 2024, were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Tellutax ​ ​ ecosio ​ ​ ecosio ​ ​ Contingent ​ ​ Contingent Consideration ​ ​ Contingent Consideration ​ ​ Consideration ​ ​ Cash Earn-out ​ ​ Stock Earn-out ​ ​ (unaudited) ​ (unaudited) (unaudited) Balance, January 1, 2024 ​ $ 4,900 ​ $ — ​ $ — ecosio acquisition (Note 3) ​ ​ — ​ ​ 71,000 ​ ​ 34,000 Fair value adjustments ​ ​ (2,275) ​ ​ — ​ ​ — Payments ​ ​ (2,325) ​ ​ — ​ ​ — Balance, September 30, 2024 ​ $ 300 ​ $ 71,000 ​ $ 34,000 ​ ​ Assets and Liabilities for Which Fair Value is Only Disclosed ​ The carrying amounts of cash and cash equivalents and the carrying amount of funds held for customers were the same as their respective fair values and are considered Level 1 measurements. The carrying amount of our bank debt approximates fair value as the variable rates on the debt approximate those commercially available in the market, and is considered a Level 3 measurement. Non-recurring Fair Value Measurements The ecosio acquisition on August 30, 2024, the Tellutax acquisition on January 25, 2021 and the Systax acquisition on January 10, 2020 were accounted for as business combinations, and the total purchase price for each acquisition was allocated to the net assets acquired and liabilities assumed based on their estimated fair values. The Company had a contractual commitment to acquire the remaining equity interest from the original Systax Quotaholders incrementally through 2024. Purchase commitment payments for these incremental acquisition amounts were based on a multiple of Systax revenue and earnings before interest, depreciation, amortization, and income taxes (“EBITDA”) performance at the end of 2023 and 2022. Management determined these future purchase commitments to be a forward contract, resulting in the Company being required to estimate and record an estimated future purchase commitment amount (the “Purchase Commitment Liability”) in connection with recording the initial purchase. The fair value of the Purchase Commitment Liability at the acquisition date was finalized to be $12,592. This amount has fluctuated as a result of changes in foreign currency exchange rates and is reflected in purchase commitment and contingent consideration liabilities in the condensed consolidated balance sheets, with such changes in exchange rates being reflected in other comprehensive loss or income in the condensed consolidated statements of comprehensive income (loss). Adjustments to the settlement date value that arose as a result of remeasurement at future balance sheet dates were recorded as interest expense related to financing costs in the condensed consolidated statements of comprehensive income (loss) in the period the change is identified. A final adjustment for $423 to interest expense was recorded during the second quarter of 2024. No such adjustments were recorded for the three or nine months ended September 30, 2023. During the second quarter of 2024, the Company paid $9,622, to acquire the remaining 20% equity interest of Systax, which increased the Company’s ownership percentage of Systax to 100%, and settled the outstanding Purchase Commitment Liability. The Purchase Commitment Liability included in purchase commitment and contingent consideration liabilities, current in the condensed consolidated balance sheet on December 31, 2023 was $9,601. The carrying amount of the Purchase Commitment Liability approximated its respective fair value at December 31, 2023 and is considered a Level 3 non-recurring fair value measurement. Derivative Instruments ​ The Company may periodically enter into derivative contracts to reduce our exposure to foreign currency exchange rates. Historically, the Company has not designated derivative contracts as hedges. Such derivative contracts are typically designed to manage specific risks according to our strategies, which may change from time to time. The Company entered into a series of foreign currency forward contracts to reduce our exposure to adverse fluctuations in the Brazilian Real associated with a portion of the Purchase Commitment Liability. Such forward contracts have not been designated as a hedge, do not qualify for hedge accounting and are not material to our condensed consolidated financial statements. During the second quarter of 2024, the forward currency contracts matured as the Company settled the outstanding Purchase Commitment Liability. These forward contacts are remeasured at fair value on a recurring basis and are included in other assets in our December 31, 2023 condensed consolidated balance sheet with changes in their estimated fair value recognized as interest expense in our condensed consolidated statements of comprehensive income (loss). Our fair value determinations are based on foreign currency exchange rates in active markets, which are considered to be Level 2 measurements within the Fair Value Hierarchy. Convertible Senior Notes ​ As of September 30, 2024 and December 31, 2023, the fair value of the were $428,418 and $0 , respectively. The fair value was determined based on the quoted price of the Notes in an over-the-counter market on the last trading day of the reporting period and has been classified as Level 2 in the fair value hierarchy.

PROPERTY AND EQUIPMENT

PROPERTY AND EQUIPMENT	9 Months Ended
	Sep. 30, 2024
PROPERTY AND EQUIPMENT
PROPERTY AND EQUIPMENT	5. PROPERTY AND EQUIPMENT The major components of property and equipment are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of September 30, ​ As of December 31, ​ ​ 2024 ​ 2023 ​ (unaudited) ​ Leasehold improvements ​ $ 20,673 ​ $ 20,662 Equipment ​ 21,924 ​ 22,012 Computer software purchased ​ 2,499 ​ 2,690 Internal-use software developed: ​ ​ ​ ​ Cloud-based customer solutions (1) ​ 237,638 ​ 142,302 Internal systems and tools ​ 67,623 ​ 39,430 Furniture and fixtures ​ 7,891 ​ 7,669 In-process internal-use software ​ 23,080 ​ 28,883 Property and equipment ​ 381,328 ​ 263,648 Less accumulated depreciation and amortization ​ (202,750) ​ (162,914) Property and equipment, net ​ $ 178,578 ​ $ 100,734 (1) Includes $63,984 related to the ecosio acquistion. For further information see Note 3, "Acquisitions". ​ Depreciation expense for property and equipment, excluding all internal-use software developed and finance leases, was $1,004 and $1,636 for the three months ended September 30, 2024 and 2023, respectively, and $3,369 Finance lease amortization was $19 and $70 for the three months ended September 30, 2024 and 2023, respectively, and $61 and $586 for the nine months ended September 30, 2024 and 2023, respectively, and is included in depreciation and amortization expense in the condensed consolidated statements of comprehensive income (loss). Assets under finance leases of $172 and $297, net of accumulated amortization of $78 and $190, respectively, at September 30, 2024 and December 31, 2023, respectively, are included in property and equipment in the condensed consolidated balance sheets. The major components of internal-use software developed are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of September 30, ​ As of December 31, ​ ​ 2024 ​ 2023 ​ (unaudited) ​ ​ Internal-use software developed ​ $ 305,261 ​ $ 181,732 Less accumulated depreciation ​ (159,866) ​ (121,646) Internal-use software developed, net of accumulated depreciation ​ 145,395 ​ 60,086 In-process internal-use software ​ 23,080 ​ 28,883 Internal-use software developed, net ​ $ 168,475 ​ $ 88,969 ​ ​ Amounts included in property and equipment additions related to capitalized internal-use software on the condensed consolidated statements of cash flows are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the nine months ended September 30, ​ ​ 2024 ​ 2023 ​ ​ (unaudited) Cloud-based customer solutions $ 32,078 ​ $ 22,170 Internal systems and tools ​ 14,683 ​ 12,095 Total ​ $ 46,761 ​ $ 34,265 ​ In-process internal-use software developed is not depreciated until it is available for its intended use. Depreciation expense for internal-use software developed for cloud-based customer solutions for the three months ended September 30, 2024 and 2023 was $7,909 and $8,821, respectively, and $25,685 and $25,230 for the nine months ended September 30, 2024 and 2023, respectively, and is included in cost of revenues, software subscriptions in the condensed consolidated statements of comprehensive income (loss). Depreciation expense for internal-use software developed for internal systems and tools for the three months ended September 30, 2024 and 2023 was $4,191 and $1,466, respectively, and $12,002 and $5,695 for the nine months ended September 30, 2024 and 2023, respectively, and is included in depreciation and amortization in the condensed consolidated statements of comprehensive income (loss).

CAPITALIZED SOFTWARE

CAPITALIZED SOFTWARE	9 Months Ended
	Sep. 30, 2024
CAPITALIZED SOFTWARE
CAPITALIZED SOFTWARE	6. CAPITALIZED SOFTWARE Capitalized software includes acquired software and direct labor and related expenses for software developed for sale for new products and enhancements to existing products. The major components of capitalized software are as follows: ​ ​ ​ ​ ​ ​ ​ ​ As of September 30, ​ As of December 31, ​ 2024 ​ 2023 ​ (unaudited) ​ ​ ​ Capitalized software $ 134,615 ​ $ 115,152 Less accumulated amortization (99,674) ​ (81,410) Capitalized software, net of accumulated depreciation 34,941 ​ 33,742 In-process capitalized software 1,924 ​ 5,029 Capitalized software, net $ 36,864 ​ $ 38,771 ​ Software development costs capitalized for the three months ended September 30, 2024 and 2023, were $5,260 and $5,041, respectively, and $16,357 and $14,083 for the nine months ended September 30, 2024 and 2023, respectively. Capitalized software amortization expense, including amortization of acquired technology, was $6,236 and $5,147 for the three months ended September 30, 2024 and 2023, respectively, and $18,264 and $13,739 for the nine months ended September 30, 2024 and 2023, respectively, and is included in cost of revenues, software subscriptions in the condensed consolidated statements of comprehensive income (loss).

GOODWILL AND OTHER INTANGIBLE A

GOODWILL AND OTHER INTANGIBLE ASSETS	9 Months Ended
	Sep. 30, 2024
GOODWILL AND OTHER INTANGIBLE ASSETS
GOODWILL AND OTHER INTANGIBLE ASSETS	7. GOODWILL AND OTHER INTANGIBLE ASSETS Goodwill and other intangible assets are as follows for the periods presented: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of September 30, ​ As of December 31, ​ ​ 2024 ​ 2023 ​ ​ (unaudited) ​ ​ ​ Goodwill ​ $ 382,449 ​ $ 257,842 Other intangible assets, net (1) ​ ​ 6,267 ​ 2,396 Total ​ $ 388,716 ​ $ 260,238 (1) ​ ​ The changes in the carrying amount of goodwill for the nine months ended September 30, 2024 are as follows: ​ ​ ​ ​ ​ ​ ​ As of September 30, ​ ​ ​ 2024 ​ ​ (unaudited) Balance, January 1 ​ $ 257,842 ecosio acquisition ​ ​ 123,509 Foreign currency translation adjustments ​ ​ 1,098 Balance, September 30, gross ​ ​ 382,449 Accumulated impairment losses ​ ​ — Balance, September 30, net ​ $ 382,449 ​ ​ The Company has recognized various amortizable other intangible assets in connection with acquisitions related to customer relationships, technology, and tradenames. The following tables provide additional information for other intangible assets, which are individually not material to the condensed consolidated financial statements, for the periods presented: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of September 30, ​ As of December 31, ​ ​ ​ ​ ​ 2024 ​ 2023 ​ ​ ​ ​ ​ (unaudited) ​ ​ ​ Weighted average amortization period (years) ​ ​ ​ ​ ​ 3.3 ​ ​ 3.5 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross value ​ ​ ​ ​ $ 16,662 ​ $ 10,960 Accumulated amortization ​ ​ ​ ​ ​ (10,395) ​ ​ (8,564) Carrying value ​ ​ ​ ​ $ 6,267 ​ $ 2,396 ​ ​ The following table presents amortization of other intangible assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the three months ended September 30, ​ ​ ​ Cost of Revenues, Software Subscriptions ​ Selling and Marketing Expense ​ ​ Total Expense 2024 ​ ​ ​ $ 55 $ 706 ​ $ 761 2023 ​ ​ ​ ​ ​ 61 ​ ​ 596 ​ ​ 657 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the nine months ended September 30, ​ ​ ​ Cost of Revenues, Software Subscriptions ​ Selling and Marketing Expense ​ ​ Total Expense 2024 ​ ​ ​ $ 174 $ 1,893 ​ ​ 2,067 2023 ​ ​ ​ ​ 181 ​ 2,046 ​ ​ 2,227 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

DEBT

DEBT	9 Months Ended
	Sep. 30, 2024
DEBT
DEBT	8. Credit Agreement The Company has a credit agreement (“Credit Agreement”) with a banking syndicate, which provided (i) a term loan in the aggregate amount of $50,000 (the “Term Loan”); and (ii) a $200,000 revolving facility (the “Line of Credit”). On April 19, 2024, the Company entered into the Fourth Amendment to the Credit Agreement (the “Fourth Amendment”) with a banking syndicate, which amended the Credit Agreement, dated as of March 31, 2020, providing for, among other things, amendments of certain definitions. Indenture and Notes ​ On April 26, 2024, the Company closed its offering of $345,000 aggregate principal amount of 0.750% Convertible Senior Notes due 2029 (the “Notes”) to qualified institutional buyers in accordance with Rule 144A under the Securities Act of 1933, as amended. The Notes were issued pursuant to, and are governed by, an indenture (the “Indenture”) between the Company and U.S. Bank Trust Company, National Association, as trustee. The Notes issued on April 26, 2024 include an additional $45,000 aggregate principal amount of Notes, issued pursuant to the full exercise by the initial purchasers of the Notes of their option to purchase additional Notes. The Notes are the senior, unsecured obligations of the Company and are (i) ranked equal in right of payment with the Company’s senior unsecured indebtedness, (ii) senior in right of payment to the Company’s indebtedness that is expressly subordinated to the Notes, (iii) effectively subordinated to the Company’s senior secured indebtedness, to the extent of the value of the collateral securing that indebtedness, and (iv) structurally subordinated to all indebtedness and other liabilities, including trade payables, and (to the extent the Company is not a holder thereof) preferred equity, if any, of the Company’s subsidiaries. ​ The Notes bear interest at a rate of 0.750% per annum on the principal amount thereof, payable semi-annually in arrears on May 1 and November 1 of each year, beginning on November 1, 2024. The Notes will mature on May 1, 2029 (the “maturity date”), unless earlier repurchased, redeemed or converted in accordance with their terms. On November 1, 2028, and thereafter, holders may convert their Notes anytime at their election, until the close of business on the second scheduled trading day immediately before the maturity date. Before November 1, 2028, holders have the right to convert their Notes only upon the occurrence of the following events: ​ ● During any calendar quarter after June 30, 2024 if the closing price of the Company's common stock for at least 20 trading days in a period of 30 consecutive trading days ending on and including the last trading day of the preceding calendar quarter is more than 130% of the then applicable conversion price (effectively $47.21 ) for the Notes per share of common stock. ● During the five business days immediately after any ten consecutive trading day period in which the trading price per $1,000 principal amount of Notes, as determined following a request by a holder of Notes, for each day of that period was less than 98% of the product of the closing price of the Company’s common stock and the then applicable conversion rate. ● If the Company calls any or all of the Notes for redemption, holders may convert all or any portion of their notes at any time prior to the close of business on the scheduled trading day prior to the redemption date, even if the Notes are not otherwise convertible at such time. ● If specified distributions to holders of the Company’s common stock are made or specified corporate events occur. If a holder converts upon a make-whole fundamental change (as defined in the Indenture) or Company redemption, the holder may be eligible to receive a make-whole premium through an increase to the conversion rate. ​ Upon conversion, the Company will pay or deliver, as applicable, cash, shares of Class A common stock or a combination of cash and shares of Class A common stock at the Company’s election. The initial conversion rate for the Notes is 27.5315 shares of Class A common stock per $1,000 principal amount of Notes, which represents an initial conversion price of approximately $36.32 per share of Class A common stock, and is subject to adjustment upon the occurrence of certain specified events as set forth in the Indenture. ​ The net proceeds from the offering of the Notes were $333,716, after deducting the initial purchasers’ discount and commissions, and other transaction and offering expenses. The Company used $42,366 of the net proceeds from this offering to fund the cost of the Capped Call Transactions (as defined below) and intends to use the remainder for working capital or other general corporate expenses, which may include capital expenditures, potential acquisitions, and strategic transactions. Capped Call Transactions ​ In connection with the pricing of the Notes on April 23, 2024, the Company entered into privately negotiated capped call transactions (the “Base Capped Calls”) with certain financial institutions (together, the “Option Counterparties”). In connection with the exercise of the option to purchase the additional Notes in full, the Company entered into additional capped call transactions with the Option Counterparties (together, the “Additional Capped Call Transactions” and, together with the Base Capped Call Transactions, the “Capped Call Transactions”). The cap price of the Capped Call Transactions will initially be $55.88 per share of Class A common stock, and is subject to certain adjustments under the terms of the Capped Call Transactions. The Capped Call Transactions are expected generally to reduce the potential dilution to the Class A common stock upon any conversion of the Notes and/or to offset any cash payments the Company is required to make in excess of the principal amount of the converted Notes, as the case may be, upon any conversion of the Notes. The Capped Call Transactions cover, subject to anti-dilution adjustments substantially similar to those applicable to the Notes, approximately 12,348 shares of the Company’s common stock. The cost of the Capped Call Transactions was $42,366 , which was included in additional paid-in capital, net of tax, in the condensed consolidated balance sheets, with no remeasurement in subsequent periods as it meets the conditions for equity classification. ​ Term Loan ​ On May 10, 2024, the Company repaid the outstanding Term Loan balance of $46,332, which included $82 of interest. The Term Loan was originally due on March 8, 2027. The Company also wrote off $276 in deferred financing fees pertaining to the Term Loan. ​ The Company’s indebtedness at September 30, 2024 and December 31, 2023 was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of September 30, 2024 ​ As of December 31, 2023 ​ ​ (unaudited) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Principal Amount ​ ​ Discounts and Deferred Financing Costs ​ ​ Net Carrying Amount ​ Principal Amount ​ ​ Discounts and Deferred Financing Costs ​ ​ Net Carrying Amount ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Term Loan $ — ​ $ — ​ $ — ​ $ 2,500 ​ $ — ​ $ 2,500 Current portion of long-term debt ​ — ​ ​ — ​ ​ — ​ ​ 2,500 ​ ​ — ​ ​ 2,500 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Term Loan ​ — ​ ​ — ​ ​ — ​ ​ 44,375 ​ ​ (316) ​ ​ 44,059 Debt, net of current portion ​ — ​ ​ — ​ ​ — ​ ​ 44,375 ​ ​ (316) ​ ​ 44,059 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Convertible senior notes, non-current ​ 345,000 ​ ​ (10,344) ​ ​ 334,656 ​ ​ — ​ ​ — ​ ​ — Total debt $ 345,000 ​ $ (10,344) ​ $ 334,656 ​ $ 46,875 ​ $ (316) ​ $ 46,559 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The Company’s interest expense related to the Notes is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the three months ended September 30, ​ ​ ​ For the nine months ended September 30, ​ ​ ​ ​ 2024 ​ ​ 2023 ​ ​ ​ 2024 ​ ​ 2023 ​ ​ ​ ​ (unaudited) ​ ​ (unaudited) Contractual interest expense ​ ​ $ 677 ​ $ — ​ ​ $ 1,108 ​ $ — Amortization of issuance costs ​ ​ ​ 564 ​ ​ — ​ ​ ​ 940 ​ ​ — Total interest expense, Convertible Senior Notes ​ ​ $ 1,241 ​ $ — ​ ​ $ 2,048 ​ $ — ​

STOCKHOLDERS' EQUITY

STOCKHOLDERS' EQUITY	9 Months Ended
	Sep. 30, 2024
STOCKHOLDERS' EQUITY
STOCKHOLDERS' EQUITY	9 . Common Stock During the three months ended September 30, 2024, the Company issued 461 shares of Class A common stock related to the exercise of options, net of 2 shares returned to the Company in lieu of payment of the exercise price and taxes due on these exercises. During this period, the Company also issued 74 shares of Class A common stock in connection with the vesting of Restricted Stock Units (“RSUs”), net of 36 shares returned to the Company in lieu of payment of taxes due on the vesting of these RSUs. During this period, the Company issued 22 shares of Class A common stock in connection with the vesting of Restricted Stock Awards (“RSAs”), net of 7 shares returned to the Company in lieu of payment of taxes due on the vesting of these RSAs. Company also issued 61 shares in connection with the ESPP and a stockholder exchanged 2,500 shares of Class B common stock, for an equivalent number of shares of Class A common stock. During the three months ended September 30, 2023, the Company issued 744 shares of Class A common stock related to the exercise of options, net of 292 shares returned to the Company in lieu of payment of the exercise price and taxes due on these exercises. During this period, the Company issued 56 shares of Class A common stock in connection with the vesting of RSUs, net of 24 shares returned to the Company in lieu of payment of taxes due on the vesting of these RSUs. During this period, the Company issued 92 shares of Class A common stock in connection with the vesting of RSAs, net of 7 shares, returned to the Company in lieu of payment of taxes due on the vesting of these RSAs, and a stockholder exchanged 879 shares of Class B common stock for an equivalent number of shares of Class A common stock.

EARNINGS PER SHARE

EARNINGS PER SHARE	9 Months Ended
	Sep. 30, 2024
EARNINGS PER SHARE
EARNINGS PER SHARE	10. EARNINGS PER SHARE The Company has two classes of common stock outstanding and thus calculates earnings per share (“EPS”) following the two-class method. This method allocates earnings for the respective periods between the two classes of common stock in proportion to the weighted average shares outstanding for each class of common stock as a percentage of total weighted average shares of both classes of common stock outstanding. Neither the Class A nor Class B common stock has any liquidity or dividend preferences and are both considered to be participating securities. ​ Basic and diluted net income (loss) per share attributable to common stockholders is calculated using the treasury stock and if-converted methods. The basic net income (loss) per share attributable to Class A common stockholders includes RSAs, RSUs, and ESPP shares once vesting or purchase contingencies are resolved, and the related shares are deemed to be outstanding. The diluted net income (loss) per share attributable to Class A common stockholders is computed by giving effect to all potential dilutive common stock equivalents outstanding for the period. For purposes of this calculation, all options to purchase shares of Class A common stock and nonvested RSAs and RSUs are considered common stock equivalents. The portion of ESPP shares for which the Company has received payments but for which the related shares are not yet issuable are also considered potential common stock equivalents. Additionally, the dilutive effect of shares issuable upon conversion of the Notes is included in the calculation of diluted EPS by application of the if-converted method. In connection with the issuance of the Notes, the Company entered into the Capped Calls Transactions, which are not included for purposes of calculating the number of diluted weighted-average shares outstanding, as their effect would be anti-dilutive. In periods of net loss available to common stockholders diluted calculations are equal to basic calculations because the inclusion of potential common stock equivalents would be anti-dilutive. The Company has excluded from the calculation of diluted EPS the effect of shares of the Company’s Class A common stock to be issued in connection with the Stock Earn-out payable to the sellers of ecosio. ​ The tables below illustrate the calculation of basic and diluted net income (loss) per common share for the Class A common stock and Class B common stock for the periods reflected below. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended September 30, ​ ​ Nine months ended September 30, ​ ​ 2024 ​ ​ 2023 ​ ​ 2024 ​ ​ 2023 ​ ​ Class A ​ ​ Class B ​ ​ Class A ​ ​ Class B ​ ​ Class A ​ ​ Class B ​ ​ Class A ​ ​ Class B ​ ​ (unaudited) ​ ​ (unaudited) Basic net income (loss) per share: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Numerator ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Allocation of net income (loss) (1) $ 3,038 ​ $ 4,183 ​ $ (1,228) ​ $ (2,171) ​ $ 6,197 ​ $ 8,872 ​ $ (9,960) ​ $ (18,467) Denominator ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total shares used in per share computation ​ 65,468 ​ 90,161 ​ ​ 54,931 ​ 97,145 ​ 63,742 ​ 91,251 ​ 53,050 ​ 98,361 Basic net income (loss) per share: $ 0.05 ​ $ 0.05 ​ $ (0.02) ​ $ (0.02) ​ $ 0.10 ​ $ 0.10 ​ $ (0.19) ​ $ (0.19) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Diluted net income (loss) per share: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Numerator ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Allocation of net income (loss) (1) $ 3,206 ​ $ 4,015 ​ $ (1,228) ​ $ (2,171) ​ $ 6,549 ​ $ 8,520 ​ $ (9,960) ​ $ (18,467) Total net income (loss) used in per diluted computation $ 3,206 ​ $ 4,015 ​ $ (1,228) ​ $ (2,171) ​ $ 6,549 ​ $ 8,520 ​ $ (9,960) ​ $ (18,467) Denominator ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Number shares used in basic per share computation ​ 65,468 ​ 90,161 ​ ​ 54,931 ​ 97,145 ​ 63,742 ​ 91,251 ​ ​ 53,050 ​ 98,361 Dilutive effect of common stock equivalents ​ 6,509 ​ — ​ ​ — ​ — ​ 6,394 ​ — ​ ​ — ​ — Total shares used in per share computation (2) ​ 71,977 ​ ​ 90,161 ​ ​ 54,931 ​ ​ 97,145 ​ ​ 70,136 ​ ​ 91,251 ​ ​ 53,050 ​ ​ 98,361 Dilutive net income (loss) per share: $ 0.04 ​ $ 0.04 ​ $ (0.02) ​ $ (0.02) ​ $ 0.09 ​ $ 0.09 ​ $ (0.19) ​ $ (0.19) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (1) (2) ​ The following weighted-average outstanding shares of common stock equivalents by award type were excluded from the computation of diluted net loss per share attributable to Class A stockholders, as the impact of including them would have been anti-dilutive: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the three months ended September 30, ​ ​ For the nine months ended September 30, ​ ​ 2024 2023 ​ ​ 2024 2023 ​ ​ (unaudited) ​ ​ (unaudited) Stock Options (1) ​ ​ — ​ ​ 7,025 ​ ​ ​ — ​ ​ 7,316 Stock Options out-of-the money options ​ ​ — ​ ​ 307 ​ ​ ​ 135 ​ ​ 498 RSAs ​ ​ — ​ ​ 121 ​ ​ ​ — ​ ​ 193 RSUs ​ ​ — ​ ​ 4,162 ​ ​ ​ — ​ ​ 3,825 ESPP ​ ​ — ​ ​ 36 ​ ​ ​ — ​ ​ 43 Convertible Senior Notes ​ ​ 8,194 ​ ​ — ​ ​ ​ 5,462 ​ ​ — ​ (1) Excludes out-of-the-money options.

STOCK-BASED AWARD PLANS

STOCK-BASED AWARD PLANS	9 Months Ended
	Sep. 30, 2024
STOCK-BASED AWARD PLANS
STOCK-BASED AWARD PLANS	11. STOCK-BASED AWARD PLANS The 2020 Incentive Award Plan (the “2020 Plan”) contributions to the Company. The Company issued stock options, RSAs, and RSUs under the 2020 Plan. As of September 30, 2024, 20,857 shares of Class A common stock were available for issuance under the 2020 Plan. ​ Options The following table summarizes activity for options outstanding under the 2020 Plan for the nine months ended September 30, 2024: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ Average ​ ​ ​ ​ ​ ​ ​ Average ​ Remaining ​ Aggregate ​ ​ ​ ​ ​ Exercise ​ Contractual ​ Intrinsic 2020 Plan Option Activity ​ Units ​ ​ Price ​ Life (Years) ​ Value ​ ​ (unaudited) Outstanding at January 1, 2024 ​ 5,692 ​ $ 5.32 ​ 4.7 ​ $ 124,327 Exercised ​ (1,576) ​ $ 3.77 ​ ​ ​ ​ ​ 2020 Plan options outstanding at September 30, 2024 ​ 4,116 ​ $ 5.91 ​ 4.4 ​ $ 134,178 2020 Plan options exercisable at September 30, 2024 3,006 ​ $ 5.48 3.9 ​ $ 99,287 ​ ​ The detail of options outstanding, vested, and exercisable under the 2020 Plan as of September 30, 2024 is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Options Outstanding ​ Options Vested and Exercisable ​ ​ Weighted ​ Weighted ​ ​ ​ ​ Average ​ ​ ​ Average Exercise Prices ​ Units ​ Life (Years) ​ Units ​ Life (Years) ​ ​ (unaudited) $0.15 to $0.71 725 ​ * ​ 725 ​ * $2.50 1,019 ​ 1.9 ​ 1,019 ​ 1.9 $3.17 217 ​ 3.6 ​ 217 ​ 3.6 $3.73 ​ 1,004 ​ 5.1 ​ 412 ​ 5.0 $4.70 ​ 541 ​ 5.4 ​ 200 ​ 5.4 $18.47 ​ 213 ​ 7.2 ​ 107 ​ 7.2 $18.96 ​ 110 ​ 6.9 ​ 110 ​ 6.9 $19.00 47 ​ 7.0 ​ 31 ​ 7.0 $32.16 240 ​ 6.4 ​ 185 ​ 6.4 ​ ​ 4,116 ​ ​ 3,006 ​ ​ *These options have indefinite contractual lives. ​ ​ ​ ​ ​ ​ ​ ​ The Board of Directors (the “Board”) intends all options granted to be exercisable at a price per share not less than the per share fair market value of the Company’s Class A common stock underlying the options on the date of grant. Compensation expense for option awards are measured based on the grant date fair value of the awards and recognized in the condensed consolidated statements of comprehensive income (loss) over the period during which the participant is required to perform the requisite services. The vesting period is generally one There were no options issued under the 2020 Plan during the three or nine months ended September 30, 2024 or 2023. ​ At September 30, 2024, $1,528 of unrecognized compensation expense associated with options is expected to be recognized over a weighted average period of approximately 0.8 ​ Restricted Stock Units The following table summarizes RSU activity for the nine months ended September 30, 2024: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ Average ​ ​ ​ ​ Grant Date Fair ​ ​ Units ​ Value Per Share Outstanding at January 1, 2024 ​ 4,171 ​ $ 16.11 Granted ​ 1,793 ​ ​ 25.73 Vested ​ (1,247) ​ ​ 16.38 Forfeited ​ (119) ​ ​ 16.42 Outstanding at September 30, 2024 ​ 4,598 ​ $ 19.77 ​ Stock-based compensation cost for RSUs is measured based on the fair value of the Company’s underlying common stock on the date of grant and is recognized on a straight-line basis in the condensed consolidated statements of comprehensive one Restricted Stock Awards The following table summarizes RSA activity for the nine months ended September 30, 2024: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ Average ​ ​ ​ ​ Grant Date Fair ​ ​ Units ​ Value Per Share Outstanding at January 1, 2024 ​ 91 ​ $ 21.50 Granted ​ 34 ​ ​ 35.06 Vested ​ (91) ​ ​ 21.50 Outstanding at September 30, 2024 34 ​ $ 35.06 ​ Stock-based compensation cost for RSAs is measured based on the fair value of the Company’s underlying common stock on the date of grant and is recognized on a straight-line basis in the condensed consolidated statements of comprehensive one Employee Stock Purchase Plan The ESPP provides eligible employees with rights during each six-month ESPP offering period to purchase shares of the Company’s Class A common stock through payroll deductions of up to a specified percentage of their eligible compensation. The purchase price of the shares, in the absence of a contrary designation, is 85% of the lower of the fair value of the Class A common stock on the first or last day of the ESPP offering period. Amounts withheld from participants are reflected in accrued salaries and benefits in the condensed consolidated balance sheets until such shares are purchased. Amounts withheld from participants for the offering period ending November 30, 2024 aggregated $1,259 as of September 30, 2024. As of September 30, 2024, 6,390 shares of Class A common stock were available for issuance under the ESPP. As of September 30, 2024, there was approximately $175 of unrecognized ESPP stock-based compensation cost expected to be recognized on a straight-line basis over the remaining term of the six-month offering period ending November 30, 2024. ​ At September 30, 2024 and 2023, there were two ESPP offering periods open that end November 30, 2024 and 2023, respectively. The fair value of ESPP purchase rights for the offering periods is comprised of the value of the 15% ESPP discount and the value associated with the call or put over the respective ESPP offering period. ESPP offering periods reflected in the September 30, 2024 and 2023 financial statements include the periods noted below in the table. The value of the call or put was estimated using the Black-Scholes model with the following assumptions: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Offering Period Ending ​ 11/30/2024 ​ 11/30/2023 ​ Fair market value of common stock $ 33.26 ​ $ 21.76 ​ Volatility 41.7 % 39.4 % Expected term (years) 0.5 ​ 0.5 ​ Expected dividend yield - % - % Risk-free interest rate 5.4 % 5.4 % ​ ​ ​ Volatility is representative of expected stock price volatility over the offering period. The Company’s volatility is applied to current and future offering periods. The expected term represents the term of the ESPP offering period, which is six months. The Company does not expect to pay dividends. The risk-free interest rate was based on the rate for a U.S. Treasury zero-coupon issue with a term that closely approximates the expected term of the award at the date nearest to the offering term. ​ Stock-Based Compensation The Company recognized total stock-based compensation cost related to incentive awards, net of forfeitures, as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the three months ended September 30, ​ For the nine months ended September 30, ​ ​ ​ 2024 2023 2024 2023 ​ ​ ​ (unaudited) ​ (unaudited) ​ Stock-based compensation expense: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Stock options ​ $ 1,219 ​ $ 1,515 ​ $ 4,969 ​ $ 4,788 ​ RSUs ​ 8,305 ​ 5,452 ​ 29,453 ​ 18,762 ​ RSAs ​ ​ 347 ​ ​ 598 ​ ​ 1,313 ​ ​ 2,076 ​ ESPP ​ 263 ​ 207 ​ 724 ​ 602 ​ Total stock-based compensation expense ​ $ 10,134 ​ $ 7,772 ​ $ 36,459 ​ $ 26,228 ​ ​ The Company recognized stock-based compensation cost in the condensed consolidated statements of comprehensive income (loss) as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the three months ended September 30, ​ For the nine months ended September 30, ​ ​ ​ 2024 2023 2024 2023 ​ ​ ​ (unaudited) ​ (unaudited) ​ Stock-based compensation expense: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cost of revenues, software subscriptions ​ $ 894 ​ $ 728 ​ $ 3,437 ​ $ 2,143 ​ Cost of revenues, services ​ 558 ​ 452 ​ 2,129 ​ 1,454 ​ Research and development ​ 2,001 ​ 1,398 ​ 7,296 ​ 4,407 ​ Selling and marketing ​ 2,951 ​ 2,325 ​ 10,101 ​ 6,305 ​ General and administrative ​ 3,730 ​ 2,869 ​ 13,496 ​ 11,919 ​ Total stock-based compensation expense ​ $ 10,134 ​ $ 7,772 ​ $ 36,459 ​ $ 26,228 ​ ​

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	9 Months Ended
	Sep. 30, 2024
COMMITMENTS AND CONTINGENCIES
COMMITMENTS AND CONTINGENCIES	12. COMMITMENTS AND CONTINGENCIES In January 2022, the Company filed a complaint against a competitor alleging claims of unfair competition, intentional interference with contractual relations, and trade secret misappropriation. The outcome of the case is subject to a number of uncertainties; therefore, the Company has not recognized any potential impact to the condensed consolidated financial statements. ​ The Company may become involved in various lawsuits and legal proceedings, which arise in the ordinary course of business. However, litigation is subject to inherent uncertainties, and an adverse result in these or other matters may arise from time to time that may harm the Company’s business. The Company is not aware of any such legal proceedings or claims that management believes will have a material adverse effect on its business, financial condition, or operating results. ​

INCOME TAXES

INCOME TAXES	9 Months Ended
	Sep. 30, 2024
INCOME TAXES
INCOME TAXES	13. INCOME TAXES The Company reported income tax (benefit) expense of $613 and $784 for the three months ended September 30, 2024 and 2023, respectively, and $(1,722) and $13,266 for the nine months ended September 30, 2024 and 2023, respectively. The effective income tax rate ("ETR") was 7.8% for the three months ended September 30, 2024, compared to (30.0)% for the three months ended September 30, 2023, and (12.9)% for the nine months ended September 30, 2024, compared to (87.5)% for the nine months ended September 30, 2023. In determining interim provisions for income taxes, the Company uses the annual estimated effective tax rate applied to the actual year-to-date income (loss) adjusted for discrete items arising year-to-date. The Company’s effective tax rate differs from the U.S. federal statutory rate of 21% primarily due to state taxes, foreign taxes, limitations on deductions of certain employees’ compensation under Internal Revenue Code Section 162(m), tax benefits on the exercises and vesting of stock awards, tax credits, and fluctuations in valuation allowances on certain foreign deferred tax assets. ​ The income tax expense for the three months ended September 30, 2024 was primarily attributable to taxes in profitable jurisdictions, fluctuations in valuation allowances on certain foreign deferred tax assets, and fluctuations in other permanent adjustments. This income tax expense was partially offset by tax benefits from stock-based awards exercised or vested during the quarter, net of the impact from limitations on deductions of certain employees’ compensation, and benefits from tax credits. The income tax benefit for the nine months ended September 30, 2024 was primarily attributable to tax benefits from stock-based awards exercised or vested, net of the impact from limitations on deductions of certain employees’ compensation, and tax credits. This income tax benefit was partially offset by taxes in profitable jurisdictions and fluctuations in valuation allowances on certain foreign deferred tax assets. The income tax expense for the three months ended September 30, 2023 was primarily attributable to fluctuations in valuation allowances on certain foreign deferred tax assets and taxes in profitable jurisdictions partially offset by tax benefits from stock-based awards exercised or vested during the quarter, net of the impact from limitations on deductions of certain employees’ compensation and benefits from tax credits. The income tax expense for the nine months ended September 30, 2023 was primarily attributable to taxes in profitable jurisdictions, fluctuations in valuation allowances on certain foreign deferred tax assets, and limitations on deductions of certain employees’ compensation partially offset by tax benefits from stock-based awards exercised or vested, and benefits from tax credits.

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS	9 Months Ended
	Sep. 30, 2024
SUBSEQUENT EVENTS
SUBSEQUENT EVENTS	14. SUBSEQUENT EVENTS On November 4, 2024, the Company entered into a Fifth Amendment to the Credit Agreement (the “Fifth Amendment”), with a banking syndicate, which amended the previous credit agreement entered into in March 2020, providing for, among other modifications, an increase in the Line of Credit commitment from $200,000 to $300,000 and an extension of the maturity date to November 4, 2029. For further information on the Credit Agreement refer to Note 8 “Debt”. ​ ​ ​ ​

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2024	Sep. 30, 2023
Pay vs Performance Disclosure
Net Income (Loss)	$ 7,221	$ 5,164	$ 2,684	$ (3,399)	$ (6,896)	$ (18,132)	$ 15,069	$ (28,427)

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Sep. 30, 2024
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

SUMMARY OF SIGNIFICANT ACCOUN_2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	9 Months Ended
	Sep. 30, 2024
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
Nature of Business	Nature of Business Vertex, Inc. (“Vertex”) and its consolidated subsidiaries and variable interest entities (“VIE”) (collectively, the “Company”) operate as solutions providers of state, local, and value added tax calculation, compliance, and analytics, offering software products that are sold through software license and software as a service (“cloud”) subscriptions. The Company also provides implementation and training services in connection with its software license and cloud subscriptions, transaction tax returns outsourcing, and other tax-related services. The Company sells to customers located throughout the United States of America (“U.S.”) and internationally.
Basis of Consolidation	Basis of Consolidation The condensed consolidated financial statements are prepared in accordance with accounting principles generally accepted in the U.S. (“U.S. GAAP”) and include the accounts of the Company. All intercompany transactions have been eliminated in consolidation. On August 30, 2024, the Company completed its acquisition of ecosio GmbH (“ecosio”). Upon its acquisition, ecosio became a wholly owned subsidiary of the Company, and its operations have been included in the Company’s condensed consolidated financial statements commencing on the acquisition date. ​ Prior to June 5, 2024, the Company owned an 80% controlling equity interest in Systax Sistemas Fiscais LTDA (“Systax”), a provider of Brazilian transaction tax content and software. Systax was determined to be a VIE and the accounts were included in the condensed consolidated financial statements. Vertex did not have full decision-making authority over Systax; however, Vertex was the entity that most significantly participated in the variability of the fair value of Systax’s net assets and was considered the entity most closely associated to Systax. As such, Vertex was deemed the primary beneficiary of Systax and consolidated Systax into its condensed consolidated financial statements. On June 5, 2024, Vertex acquired the remaining 20% equity interest in Systax. Systax is now a wholly owned subsidiary of the Company and is consolidated into the condensed consolidated financial statements.
Unaudited Interim Financial Information	Unaudited Interim Financial Information The accompanying unaudited interim condensed consolidated financial statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”) for interim financial information and include the accounts of the Company. Certain information and disclosures normally included in consolidated financial statements prepared in accordance with U.S. GAAP have been condensed or omitted. Accordingly, these interim condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and the related notes for the year ended December 31, 2023 included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2023 (the “2023 Annual Report”) filed with the SEC on February 29, 2024. The condensed consolidated balance sheet as of December 31, 2023 has been derived from audited financial statements included in the 2023 Annual Report. The accompanying interim condensed consolidated balance sheet as of September 30, 2024, the interim condensed consolidated statements of comprehensive income (loss) and changes in stockholders’ equity for the three and nine months ended September 30, 2024 and 2023, and the interim condensed consolidated statements of cash flows for the nine months ended September 30, 2024 and 2023 are unaudited. The unaudited interim condensed consolidated financial statements have been prepared on a basis consistent with that used to prepare the annual audited consolidated financial statements and include, in the opinion of management, all adjustments, consisting of normal and recurring items necessary for the fair presentation of the condensed consolidated financial statements. The operating results for the three and nine months ended September 30, 2024 are not necessarily indicative of the results expected for the full year ending December 31, 2024.
Segments	Segments The Company operates its business as one operating segment. For the three and nine months ended September 30, 2024, approximately 8% and 7%, respectively, of the Company’s revenues were generated from customers located outside the U.S. For both the three and nine months ended September 30, 2023, approximately 7% of the Company’s revenues were generated from customers located outside the U.S. As of September 30, 2024 and December 31, 2023, $654 and $633, respectively, of the Company’s tangible property and equipment assets were held outside the U.S.
Use of Estimates	Use of Estimates The preparation of condensed consolidated financial statements requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, equity, revenues, and expenses during the reporting period. Significant estimates used in preparing these condensed consolidated financial statements include: (i) the estimated allowance for subscription cancellations; (ii) expected credit losses associated with the allowance for doubtful accounts; (iii) allowance for credit losses on available-for-sale debt securities; (iv) the reserve for self-insurance; (v) assumptions related to achievement of technological feasibility for software developed for sale; (vi) product life cycles; (vii) estimated useful lives and potential impairment of long-lived assets, intangible assets, and capitalized cloud computing arrangement (“CCA”) software implementation costs; (viii) potential impairment of goodwill; (ix) determination of the fair value of tangible and intangible assets acquired, liabilities assumed, and consideration transferred in acquisitions; (x) amortization period of deferred commissions; (xi) Black-Scholes-Merton option pricing model (“Black-Scholes model”) input assumptions used to determine the fair value of certain stock-based compensation awards and Employee Stock Purchase Plan (“ESPP”) purchase rights; (xii) measurement of future purchase commitment, fair value of contingent consideration liabilities related to cash and stock earn-out payments, and deferred purchase consideration liabilities associated with acquisitions; and (xiii) the potential outcome of future tax consequences of events that have been recognized in the condensed consolidated financial statements or tax returns. Actual results may differ from these estimates.
Convertible Senior Notes	Convertible Senior Notes The Company accounts for its convertible senior notes (the “Notes”) wholly as debt under ASU 2026-06 Debt—Debt with Conversion and Other Options (Subtopic 470-20.) ​ Capped Call Transactions ​ Derivatives and Hedging
Supplemental Balance Sheet Disclosures	Supplemental Balance Sheet Disclosures Supplemental balance sheet disclosures are as follows for the respective periods: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of September 30, ​ ​ As of December 31, ​ 2024 ​ 2023 ​ (unaudited) ​ ​ ​ Prepaid expenses and other current assets: ​ ​ Prepaid expenses ​ $ 12,534 ​ $ 11,558 Unamortized cloud computing implementation costs ​ ​ 3,995 ​ ​ 3,995 Prepaid insurance ​ ​ 995 ​ ​ 521 Prepaid licenses and support ​ ​ 16,339 ​ ​ 10,099 Prepaid expenses and other current assets ​ $ 33,863 ​ $ 26,173 ​ ​ ​ ​ ​ ​ ​ Other assets: ​ ​ ​ ​ Unamortized cloud computing implementation costs ​ $ 10,866 ​ $ 12,475 Other assets ​ ​ 2,897 ​ ​ 3,538 Total other assets ​ $ 13,763 ​ $ 16,013 ​ ​ ​ ​ ​ ​ ​ Accrued expenses: ​ ​ ​ ​ ​ ​ Accrued general expenses ​ $ 20,472 ​ $ 25,998 Accrued contract labor and professional fees ​ ​ 18,344 ​ ​ 13,372 Accrued income and other taxes ​ ​ 5,827 ​ ​ 5,365 Accrued expenses ​ $ 44,643 ​ $ 44,735 ​ ​ ​ ​ ​ ​ ​ ​ Cloud computing software implementation costs incurred in hosting arrangements are capitalized and reported as a component of prepaid expenses and other current assets, or other assets, once available for their intended use. These costs are amortized using the straight-line method over their respective contract service periods, including periods covered by an option to extend, ranging from two
Recently Issued or Adopted Accounting Pronouncements	Recently Issued or Adopted Accounting Pronouncements Segment Reporting Income Tax Disclosures ​

SUMMARY OF SIGNIFICANT ACCOUN_3

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	9 Months Ended
	Sep. 30, 2024
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
Schedule of supplemental balance sheet information	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of September 30, ​ ​ As of December 31, ​ 2024 ​ 2023 ​ (unaudited) ​ ​ ​ Prepaid expenses and other current assets: ​ ​ Prepaid expenses ​ $ 12,534 ​ $ 11,558 Unamortized cloud computing implementation costs ​ ​ 3,995 ​ ​ 3,995 Prepaid insurance ​ ​ 995 ​ ​ 521 Prepaid licenses and support ​ ​ 16,339 ​ ​ 10,099 Prepaid expenses and other current assets ​ $ 33,863 ​ $ 26,173 ​ ​ ​ ​ ​ ​ ​ Other assets: ​ ​ ​ ​ Unamortized cloud computing implementation costs ​ $ 10,866 ​ $ 12,475 Other assets ​ ​ 2,897 ​ ​ 3,538 Total other assets ​ $ 13,763 ​ $ 16,013 ​ ​ ​ ​ ​ ​ ​ Accrued expenses: ​ ​ ​ ​ ​ ​ Accrued general expenses ​ $ 20,472 ​ $ 25,998 Accrued contract labor and professional fees ​ ​ 18,344 ​ ​ 13,372 Accrued income and other taxes ​ ​ 5,827 ​ ​ 5,365 Accrued expenses ​ $ 44,643 ​ $ 44,735 ​ ​ ​ ​ ​ ​ ​

REVENUE RECOGNITION (Tables)

REVENUE RECOGNITION (Tables)	9 Months Ended
	Sep. 30, 2024
REVENUE RECOGNITION
Schedule of disaggregation of revenue	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended September 30, Nine months ended September 30, ​ ​ 2024 2023 ​ 2024 2023 ​ (unaudited) (unaudited) Software subscriptions: ​ ​ ​ ​ ​ ​ ​ ​ ​ Software licenses ​ $ 75,273 ​ $ 66,637 $ 215,365 ​ $ 196,070 Cloud subscriptions ​ ​ 70,981 ​ ​ 54,648 ​ 199,162 ​ ​ 154,065 Software subscriptions ​ ​ 146,254 ​ ​ 121,285 ​ 414,527 ​ ​ 350,135 Services ​ 24,181 ​ 23,742 73,793 ​ 67,338 Total revenues ​ $ 170,435 ​ $ 145,027 ​ $ 488,320 ​ $ 417,473
Schedule of beginning and ending balances of accounts receivable, net of allowance	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the nine months ended September 30, 2024 ​ For the year ended December 31, 2023 ​ ​ (unaudited) ​ ​ ​ Balance, beginning of period ​ $ 141,752 ​ $ 102,885 Balance, end of period ​ 129,908 ​ 141,752 Increase (decrease), net ​ $ (11,844) ​ $ 38,867
Schedule of beginning and ending balances of and changes to the allowance and the deferred allowance	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the three months ended September 30, ​ ​ 2024 ​ 2023 ​ ​ Balance ​ Net Change Balance ​ Net Change ​ ​ (unaudited) Allowance balance, July 1, ​ $ (17,704) ​ ​ $ (14,218) ​ Allowance balance, September 30, ​ (14,273) ​ ​ (14,308) ​ Change in allowance ​ ​ ​ $ (3,431) ​ ​ ​ $ 90 Deferred allowance balance, July 1, ​ 12,753 ​ ​ 10,409 ​ Deferred allowance balance, September 30, ​ 10,235 ​ ​ 10,472 ​ Change in deferred allowance ​ ​ ​ 2,518 ​ ​ ​ (63) Net amount charged to revenues ​ ​ ​ $ (913) ​ ​ ​ $ 27 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the nine months ended September 30, ​ ​ 2024 ​ 2023 ​ ​ Balance ​ Net Change Balance ​ Net Change ​ ​ (unaudited) Allowance balance, January 1, ​ $ (16,272) ​ ​ $ (9,554) ​ Allowance balance, September 30, ​ (14,273) ​ ​ (14,308) ​ Change in allowance ​ ​ ​ $ (1,999) ​ ​ ​ $ 4,754 Deferred allowance balance, January 1, ​ 11,741 ​ ​ 7,133 ​ Deferred allowance balance, September 30, ​ 10,235 ​ ​ 10,472 ​ Change in deferred allowance ​ ​ ​ 1,506 ​ ​ ​ (3,339) Net amount charged to revenues ​ ​ ​ $ (493) ​ ​ ​ $ 1,415 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​
Schedule of information about the balances of and changes to deferred revenue	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the three months ended September 30, ​ For the nine months ended September 30, ​ ​ 2024 ​ 2023 ​ 2024 ​ 2023 ​ ​ (unaudited) ​ (unaudited) Changes to deferred revenue: ​ ​ ​ ​ Beginning balance ​ $ 299,741 ​ $ 277,053 ​ $ 292,720 ​ $ 279,136 Additional amounts deferred ​ 175,106 ​ 134,789 ​ 500,012 ​ 405,152 Revenues recognized ​ (170,435) ​ (145,027) ​ (488,320) ​ (417,473) Ending balance ​ $ 304,412 ​ $ 266,815 ​ $ 304,412 ​ $ 266,815
Schedule of information about the changes to contract cost balances	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the three months ended September 30, ​ For the nine months ended September 30, ​ ​ 2024 ​ 2023 ​ 2024 ​ 2023 ​ ​ (unaudited) ​ (unaudited) Deferred commissions: ​ ​ ​ ​ Beginning balance ​ $ 21,862 ​ $ 16,726 ​ $ 21,237 ​ $ 15,463 Additions ​ 5,024 ​ 3,839 ​ 13,793 ​ 9,437 Amortization ​ (4,346) ​ (3,471) ​ (12,490) ​ (7,806) Ending balance ​ $ 22,540 ​ $ 17,094 ​ $ 22,540 ​ $ 17,094 ​

ACQUISITIONS (Tables)

ACQUISITIONS (Tables)	9 Months Ended
	Sep. 30, 2024
ACQUISITIONS
Schedule of purchase price and assets acquired and liabilities assumed	​ ​ ​ ​ ​ August 30, 2024 ​ (unaudited) Upfront cash consideration $ 64,829 Cash and Stock Earn-outs, at fair value ​ 105,000 Total $ 169,829 ​ ​ ​ ​ ​ August 30, 2024 ​ ​ (unaudited) Cash and cash equivalents $ 788 Accounts receivable ​ 2,068 Prepaid expenses and other current assets ​ 475 Property and equipment (1) ​ 63,984 Other assets ​ 34 Goodwill (2) ​ 123,509 Other intangibles ​ 5,950 Accounts payable ​ (1,118) Third-party debt ​ (3,904) Accrued expenses ​ (5,184) Deferred revenue ​ (752) Deferred income tax ​ (16,021) Total $ 169,829 (1) ​ ​ (2) ​ ​ ​ ​ ​
Schedule of acquired intangible assets	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ August 30, 2024 (unaudited) ecosio Identifiable Intangibles ​ Balance Sheet Location ​ ​ Fair Value ​ Valuation Methodology ​ Estimated Useful Life ​ Discount Rate ​ Developed technology ​ Property and equipment, net ​ $ 63,800 ​ Multi-period excess earnings method - income approach ​ 7 years ​ 15.5 % Trade name ​ Goodwill and other intangible assets ​ $ 1,450 ​ Relief from royalty method - income approach ​ 3 years ​ 15.5 % Customer relationships ​ Goodwill and other intangible assets ​ $ 4,500 ​ With and without method - income approach ​ 3 years ​ 15.5 %

FINANCIAL INSTRUMENTS AND FAI_2

FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS (Tables)	9 Months Ended
	Sep. 30, 2024
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Schedule of assets and liabilities measured at fair value on a recurring basis	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurements Using As of September 30, 2024 (unaudited) ​ Fair Value Prices in active markets for identical assets (Level 1) Significant other observable inputs (Level 2) Significant unobservable inputs (Level 3) Money Market Funds ​ $ 249,150 ​ $ 249,150 ​ ​ — ​ ​ — Commercial Paper ​ ​ 6,451 ​ ​ — ​ ​ 6,451 ​ ​ — U.S. Treasury Securities ​ ​ 4,500 ​ ​ — ​ ​ 4,500 ​ ​ — Tellutax Contingent Consideration ​ ​ 300 ​ ​ — ​ ​ — ​ ​ 300 ecosio Cash Earn-out ​ ​ 71,000 ​ ​ — ​ ​ — ​ ​ 71,000 ecosio Stock Earn-out ​ ​ 34,000 ​ ​ — ​ ​ — ​ ​ 34,000 ​ ​ Fair Value Measurements Using As of December 31, 2023 ​ Fair Value Prices in active markets for identical assets (Level 1) Significant other observable inputs (Level 2) Significant unobservable inputs (Level 3) Money Market Funds ​ $ 53,049 ​ $ 53,049 ​ $ — ​ $ — Commercial Paper ​ ​ 7,168 ​ ​ — ​ ​ 7,168 ​ ​ — U.S. Treasury Securities ​ ​ 3,621 ​ ​ — ​ ​ 3,621 ​ ​ — Tellutax Contingent Consideration ​ ​ 4,900 ​ ​ — ​ ​ — ​ ​ 4,900 Foreign Currency Forward Contracts ​ ​ 849 ​ ​ — ​ ​ 849 ​ ​ —
Schedule of additional information on Cash and Stock Earn-outs	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash Earn-out ​ ​ Fair value Cash Earn-out/ Period (unaudited) ​ ​ At 100% Achievement ​ ​ At acquisition Year 1 - December 1, 2024 - December 1, 2025 ​ $ 16,000 ​ $ 16,700 Year 2 - December 1, 2025 - December 1, 2026 ​ ​ 25,000 ​ ​ 23,200 Year 3 - December 1, 2026 - December 1, 2027 ​ ​ 35,000 ​ ​ 31,100 Total Cash Earn-out ​ $ 76,000 ​ $ 71,000 ​ ​ ​ Maximum ​ ​ Fair value Stock Earn-out/ Period (unaudited) ​ ​ Payout ​ ​ At acquisition Year 1 - December 1, 2024 - December 1, 2025 ​ $ 12,000 ​ $ 12,200 Year 2 - December 1, 2025 - December 1, 2026 ​ ​ 12,000 ​ ​ 11,400 Year 3 - December 1, 2026 - December 1, 2027 ​ ​ 11,000 ​ ​ 10,400 Total Stock Earn-out ​ $ 35,000 ​ $ 34,000 ​ ​ ​ ​ ​ ​ ​
Changes in fair value of contingent consideration	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Tellutax ​ ​ ecosio ​ ​ ecosio ​ ​ Contingent ​ ​ Contingent Consideration ​ ​ Contingent Consideration ​ ​ Consideration ​ ​ Cash Earn-out ​ ​ Stock Earn-out ​ ​ (unaudited) ​ (unaudited) (unaudited) Balance, January 1, 2024 ​ $ 4,900 ​ $ — ​ $ — ecosio acquisition (Note 3) ​ ​ — ​ ​ 71,000 ​ ​ 34,000 Fair value adjustments ​ ​ (2,275) ​ ​ — ​ ​ — Payments ​ ​ (2,325) ​ ​ — ​ ​ — Balance, September 30, 2024 ​ $ 300 ​ $ 71,000 ​ $ 34,000
Ecosio
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Summary of fair value of contingent consideration and unobservable inputs used for the Monte Carlo Simulation valuation	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2024 (unaudited) Liabilities Fair Value ​ Valuation Technique ​ Unobservable Inputs ecosio Contingent Consideration - Cash Earn-out ​ $ 71,000 ​ ​ Monte Carlo Simulation ​ ​ Revenue volatility ​ 21.0 % ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue discount rate ​ 7.6 % ​ ​ ​ ​ ​ ​ ​ ​ ​ Term (in years) ​ 3.0 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ecosio Contingent Consideration - Stock Earn-out ​ $ 34,000 ​ ​ Monte Carlo Simulation ​ ​ Revenue volatility ​ 21.0 % ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue discount rate ​ 7.6 % ​ ​ ​ ​ ​ ​ ​ ​ ​ Term (in years) ​ 3.0 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​
Tellutax
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Summary of fair value of contingent consideration and unobservable inputs used for the Monte Carlo Simulation valuation	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2024 (unaudited) Liabilities Fair Value ​ Valuation Technique ​ Unobservable Inputs Tellutax Contingent Consideration ​ $ 300 ​ ​ Monte Carlo Simulation ​ ​ Revenue volatility ​ 50.0 % ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue discount rate ​ 20.2 % ​ ​ ​ ​ ​ ​ ​ ​ ​ Term (in years) ​ 0.6 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2023 Liability Fair Value ​ Valuation Technique ​ Unobservable Inputs Tellutax Contingent Consideration ​ $ 4,900 ​ ​ Monte Carlo Simulation ​ ​ Revenue volatility ​ 60.0 % ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue discount rate ​ 20.8 % ​ ​ ​ ​ ​ ​ ​ ​ ​ Term (in years) ​ 1.3 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

PROPERTY AND EQUIPMENT (Tables)

PROPERTY AND EQUIPMENT (Tables)	9 Months Ended
	Sep. 30, 2024
PROPERTY AND EQUIPMENT
Schedule of major components of property and equipment	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of September 30, ​ As of December 31, ​ ​ 2024 ​ 2023 ​ (unaudited) ​ Leasehold improvements ​ $ 20,673 ​ $ 20,662 Equipment ​ 21,924 ​ 22,012 Computer software purchased ​ 2,499 ​ 2,690 Internal-use software developed: ​ ​ ​ ​ Cloud-based customer solutions (1) ​ 237,638 ​ 142,302 Internal systems and tools ​ 67,623 ​ 39,430 Furniture and fixtures ​ 7,891 ​ 7,669 In-process internal-use software ​ 23,080 ​ 28,883 Property and equipment ​ 381,328 ​ 263,648 Less accumulated depreciation and amortization ​ (202,750) ​ (162,914) Property and equipment, net ​ $ 178,578 ​ $ 100,734 (1) Includes $63,984 related to the ecosio acquistion. For further information see Note 3, "Acquisitions".
Schedule of major components of internal-use software	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of September 30, ​ As of December 31, ​ ​ 2024 ​ 2023 ​ (unaudited) ​ ​ Internal-use software developed ​ $ 305,261 ​ $ 181,732 Less accumulated depreciation ​ (159,866) ​ (121,646) Internal-use software developed, net of accumulated depreciation ​ 145,395 ​ 60,086 In-process internal-use software ​ 23,080 ​ 28,883 Internal-use software developed, net ​ $ 168,475 ​ $ 88,969
Schedule of amounts capitalized for internal-use software and included in property and equipment additions on the consolidated statements of cash flows	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the nine months ended September 30, ​ ​ 2024 ​ 2023 ​ ​ (unaudited) Cloud-based customer solutions $ 32,078 ​ $ 22,170 Internal systems and tools ​ 14,683 ​ 12,095 Total ​ $ 46,761 ​ $ 34,265

CAPITALIZED SOFTWARE (Tables)

CAPITALIZED SOFTWARE (Tables)	9 Months Ended
	Sep. 30, 2024
CAPITALIZED SOFTWARE
Schedule of major components of capitalized software	​ ​ ​ ​ ​ ​ ​ ​ As of September 30, ​ As of December 31, ​ 2024 ​ 2023 ​ (unaudited) ​ ​ ​ Capitalized software $ 134,615 ​ $ 115,152 Less accumulated amortization (99,674) ​ (81,410) Capitalized software, net of accumulated depreciation 34,941 ​ 33,742 In-process capitalized software 1,924 ​ 5,029 Capitalized software, net $ 36,864 ​ $ 38,771

GOODWILL AND OTHER INTANGIBLE_2

GOODWILL AND OTHER INTANGIBLE ASSETS (Tables)	9 Months Ended
	Sep. 30, 2024
GOODWILL AND OTHER INTANGIBLE ASSETS
Changes in the carrying amount of goodwill	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of September 30, ​ As of December 31, ​ ​ 2024 ​ 2023 ​ ​ (unaudited) ​ ​ ​ Goodwill ​ $ 382,449 ​ $ 257,842 Other intangible assets, net (1) ​ ​ 6,267 ​ 2,396 Total ​ $ 388,716 ​ $ 260,238 (1) ​ ​ ​ ​ ​ ​ ​ As of September 30, ​ ​ ​ 2024 ​ ​ (unaudited) Balance, January 1 ​ $ 257,842 ecosio acquisition ​ ​ 123,509 Foreign currency translation adjustments ​ ​ 1,098 Balance, September 30, gross ​ ​ 382,449 Accumulated impairment losses ​ ​ — Balance, September 30, net ​ $ 382,449
Schedule of other acquired intangible assets	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of September 30, ​ As of December 31, ​ ​ ​ ​ ​ 2024 ​ 2023 ​ ​ ​ ​ ​ (unaudited) ​ ​ ​ Weighted average amortization period (years) ​ ​ ​ ​ ​ 3.3 ​ ​ 3.5 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross value ​ ​ ​ ​ $ 16,662 ​ $ 10,960 Accumulated amortization ​ ​ ​ ​ ​ (10,395) ​ ​ (8,564) Carrying value ​ ​ ​ ​ $ 6,267 ​ $ 2,396
Schedule of acquired intangible assets	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the three months ended September 30, ​ ​ ​ Cost of Revenues, Software Subscriptions ​ Selling and Marketing Expense ​ ​ Total Expense 2024 ​ ​ ​ $ 55 $ 706 ​ $ 761 2023 ​ ​ ​ ​ ​ 61 ​ ​ 596 ​ ​ 657 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the nine months ended September 30, ​ ​ ​ Cost of Revenues, Software Subscriptions ​ Selling and Marketing Expense ​ ​ Total Expense 2024 ​ ​ ​ $ 174 $ 1,893 ​ ​ 2,067 2023 ​ ​ ​ ​ 181 ​ 2,046 ​ ​ 2,227 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

DEBT (Tables)

DEBT (Tables)	9 Months Ended
	Sep. 30, 2024
DEBT
Schedule of Debt	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of September 30, 2024 ​ As of December 31, 2023 ​ ​ (unaudited) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Principal Amount ​ ​ Discounts and Deferred Financing Costs ​ ​ Net Carrying Amount ​ Principal Amount ​ ​ Discounts and Deferred Financing Costs ​ ​ Net Carrying Amount ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Term Loan $ — ​ $ — ​ $ — ​ $ 2,500 ​ $ — ​ $ 2,500 Current portion of long-term debt ​ — ​ ​ — ​ ​ — ​ ​ 2,500 ​ ​ — ​ ​ 2,500 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Term Loan ​ — ​ ​ — ​ ​ — ​ ​ 44,375 ​ ​ (316) ​ ​ 44,059 Debt, net of current portion ​ — ​ ​ — ​ ​ — ​ ​ 44,375 ​ ​ (316) ​ ​ 44,059 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Convertible senior notes, non-current ​ 345,000 ​ ​ (10,344) ​ ​ 334,656 ​ ​ — ​ ​ — ​ ​ — Total debt $ 345,000 ​ $ (10,344) ​ $ 334,656 ​ $ 46,875 ​ $ (316) ​ $ 46,559
Schedule Of Interest Expense Debt	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the three months ended September 30, ​ ​ ​ For the nine months ended September 30, ​ ​ ​ ​ 2024 ​ ​ 2023 ​ ​ ​ 2024 ​ ​ 2023 ​ ​ ​ ​ (unaudited) ​ ​ (unaudited) Contractual interest expense ​ ​ $ 677 ​ $ — ​ ​ $ 1,108 ​ $ — Amortization of issuance costs ​ ​ ​ 564 ​ ​ — ​ ​ ​ 940 ​ ​ — Total interest expense, Convertible Senior Notes ​ ​ $ 1,241 ​ $ — ​ ​ $ 2,048 ​ $ — ​

EARNINGS PER SHARE (Tables)

EARNINGS PER SHARE (Tables)	9 Months Ended
	Sep. 30, 2024
EARNINGS PER SHARE
Schedule of earnings per share basic and diluted	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended September 30, ​ ​ Nine months ended September 30, ​ ​ 2024 ​ ​ 2023 ​ ​ 2024 ​ ​ 2023 ​ ​ Class A ​ ​ Class B ​ ​ Class A ​ ​ Class B ​ ​ Class A ​ ​ Class B ​ ​ Class A ​ ​ Class B ​ ​ (unaudited) ​ ​ (unaudited) Basic net income (loss) per share: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Numerator ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Allocation of net income (loss) (1) $ 3,038 ​ $ 4,183 ​ $ (1,228) ​ $ (2,171) ​ $ 6,197 ​ $ 8,872 ​ $ (9,960) ​ $ (18,467) Denominator ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total shares used in per share computation ​ 65,468 ​ 90,161 ​ ​ 54,931 ​ 97,145 ​ 63,742 ​ 91,251 ​ 53,050 ​ 98,361 Basic net income (loss) per share: $ 0.05 ​ $ 0.05 ​ $ (0.02) ​ $ (0.02) ​ $ 0.10 ​ $ 0.10 ​ $ (0.19) ​ $ (0.19) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Diluted net income (loss) per share: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Numerator ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Allocation of net income (loss) (1) $ 3,206 ​ $ 4,015 ​ $ (1,228) ​ $ (2,171) ​ $ 6,549 ​ $ 8,520 ​ $ (9,960) ​ $ (18,467) Total net income (loss) used in per diluted computation $ 3,206 ​ $ 4,015 ​ $ (1,228) ​ $ (2,171) ​ $ 6,549 ​ $ 8,520 ​ $ (9,960) ​ $ (18,467) Denominator ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Number shares used in basic per share computation ​ 65,468 ​ 90,161 ​ ​ 54,931 ​ 97,145 ​ 63,742 ​ 91,251 ​ ​ 53,050 ​ 98,361 Dilutive effect of common stock equivalents ​ 6,509 ​ — ​ ​ — ​ — ​ 6,394 ​ — ​ ​ — ​ — Total shares used in per share computation (2) ​ 71,977 ​ ​ 90,161 ​ ​ 54,931 ​ ​ 97,145 ​ ​ 70,136 ​ ​ 91,251 ​ ​ 53,050 ​ ​ 98,361 Dilutive net income (loss) per share: $ 0.04 ​ $ 0.04 ​ $ (0.02) ​ $ (0.02) ​ $ 0.09 ​ $ 0.09 ​ $ (0.19) ​ $ (0.19) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (1) (2)
Schedule of weighted-average outstanding shares of common stock equivalents	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the three months ended September 30, ​ ​ For the nine months ended September 30, ​ ​ 2024 2023 ​ ​ 2024 2023 ​ ​ (unaudited) ​ ​ (unaudited) Stock Options (1) ​ ​ — ​ ​ 7,025 ​ ​ ​ — ​ ​ 7,316 Stock Options out-of-the money options ​ ​ — ​ ​ 307 ​ ​ ​ 135 ​ ​ 498 RSAs ​ ​ — ​ ​ 121 ​ ​ ​ — ​ ​ 193 RSUs ​ ​ — ​ ​ 4,162 ​ ​ ​ — ​ ​ 3,825 ESPP ​ ​ — ​ ​ 36 ​ ​ ​ — ​ ​ 43 Convertible Senior Notes ​ ​ 8,194 ​ ​ — ​ ​ ​ 5,462 ​ ​ — ​ (1) Excludes out-of-the-money options.

STOCK-BASED AWARD PLANS (Tables

STOCK-BASED AWARD PLANS (Tables)	9 Months Ended
	Sep. 30, 2024
Compensation plans:
Schedule of ESPP valuation assumptions	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Offering Period Ending ​ 11/30/2024 ​ 11/30/2023 ​ Fair market value of common stock $ 33.26 ​ $ 21.76 ​ Volatility 41.7 % 39.4 % Expected term (years) 0.5 ​ 0.5 ​ Expected dividend yield - % - % Risk-free interest rate 5.4 % 5.4 %
Schedule of stock-based compensation cost related to incentive awards	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the three months ended September 30, ​ For the nine months ended September 30, ​ ​ ​ 2024 2023 2024 2023 ​ ​ ​ (unaudited) ​ (unaudited) ​ Stock-based compensation expense: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Stock options ​ $ 1,219 ​ $ 1,515 ​ $ 4,969 ​ $ 4,788 ​ RSUs ​ 8,305 ​ 5,452 ​ 29,453 ​ 18,762 ​ RSAs ​ ​ 347 ​ ​ 598 ​ ​ 1,313 ​ ​ 2,076 ​ ESPP ​ 263 ​ 207 ​ 724 ​ 602 ​ Total stock-based compensation expense ​ $ 10,134 ​ $ 7,772 ​ $ 36,459 ​ $ 26,228 ​
Schedule of stock based compensation cost in consolidated statement of operations	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the three months ended September 30, ​ For the nine months ended September 30, ​ ​ ​ 2024 2023 2024 2023 ​ ​ ​ (unaudited) ​ (unaudited) ​ Stock-based compensation expense: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cost of revenues, software subscriptions ​ $ 894 ​ $ 728 ​ $ 3,437 ​ $ 2,143 ​ Cost of revenues, services ​ 558 ​ 452 ​ 2,129 ​ 1,454 ​ Research and development ​ 2,001 ​ 1,398 ​ 7,296 ​ 4,407 ​ Selling and marketing ​ 2,951 ​ 2,325 ​ 10,101 ​ 6,305 ​ General and administrative ​ 3,730 ​ 2,869 ​ 13,496 ​ 11,919 ​ Total stock-based compensation expense ​ $ 10,134 ​ $ 7,772 ​ $ 36,459 ​ $ 26,228 ​ ​
Employee Stock Option
Compensation plans:
Schedule of Option activity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ Average ​ ​ ​ ​ ​ ​ ​ Average ​ Remaining ​ Aggregate ​ ​ ​ ​ ​ Exercise ​ Contractual ​ Intrinsic 2020 Plan Option Activity ​ Units ​ ​ Price ​ Life (Years) ​ Value ​ ​ (unaudited) Outstanding at January 1, 2024 ​ 5,692 ​ $ 5.32 ​ 4.7 ​ $ 124,327 Exercised ​ (1,576) ​ $ 3.77 ​ ​ ​ ​ ​ 2020 Plan options outstanding at September 30, 2024 ​ 4,116 ​ $ 5.91 ​ 4.4 ​ $ 134,178 2020 Plan options exercisable at September 30, 2024 3,006 ​ $ 5.48 3.9 ​ $ 99,287
Schedule of outstanding, vested and exercisable	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Options Outstanding ​ Options Vested and Exercisable ​ ​ Weighted ​ Weighted ​ ​ ​ ​ Average ​ ​ ​ Average Exercise Prices ​ Units ​ Life (Years) ​ Units ​ Life (Years) ​ ​ (unaudited) $0.15 to $0.71 725 ​ * ​ 725 ​ * $2.50 1,019 ​ 1.9 ​ 1,019 ​ 1.9 $3.17 217 ​ 3.6 ​ 217 ​ 3.6 $3.73 ​ 1,004 ​ 5.1 ​ 412 ​ 5.0 $4.70 ​ 541 ​ 5.4 ​ 200 ​ 5.4 $18.47 ​ 213 ​ 7.2 ​ 107 ​ 7.2 $18.96 ​ 110 ​ 6.9 ​ 110 ​ 6.9 $19.00 47 ​ 7.0 ​ 31 ​ 7.0 $32.16 240 ​ 6.4 ​ 185 ​ 6.4 ​ ​ 4,116 ​ ​ 3,006 ​ ​ *These options have indefinite contractual lives. ​ ​ ​ ​ ​ ​ ​
Restricted Stock Units
Compensation plans:
Schedule of Option activity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ Average ​ ​ ​ ​ Grant Date Fair ​ ​ Units ​ Value Per Share Outstanding at January 1, 2024 ​ 4,171 ​ $ 16.11 Granted ​ 1,793 ​ ​ 25.73 Vested ​ (1,247) ​ ​ 16.38 Forfeited ​ (119) ​ ​ 16.42 Outstanding at September 30, 2024 ​ 4,598 ​ $ 19.77
Restricted Stock Awards
Compensation plans:
Schedule of restricted activity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ Average ​ ​ ​ ​ Grant Date Fair ​ ​ Units ​ Value Per Share Outstanding at January 1, 2024 ​ 91 ​ $ 21.50 Granted ​ 34 ​ ​ 35.06 Vested ​ (91) ​ ​ 21.50 Outstanding at September 30, 2024 34 ​ $ 35.06

SUMMARY OF SIGNIFICANT ACCOUN_4

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) - Systax	Sep. 30, 2024	Jun. 05, 2024	Jun. 04, 2024
Summary of significant accounting policies
Equity interest held by entity before the acquisition date			80%
Equity interest acquired	20%	20%

SUMMARY OF SIGNIFICANT ACCOUN_5

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Concentration of Credit Risk (Details) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2024 USD ($)	Sep. 30, 2024 USD ($) segment	Sep. 30, 2023	Dec. 31, 2023 USD ($)
Segment information:
Operating segments | segment		1
Property and equipment	$ 168,475	$ 168,475		$ 88,969
Outside of the United States
Segment information:
Property and equipment	$ 654	$ 654		$ 633
Revenue | Geographic Concentration Risk | Outside of the United States
Segment information:
Risk percentage	8%	7%	7%

SUMMARY OF SIGNIFICANT ACCOUN_6

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Software Development Costs and Supplemental Balance Sheet Disclosures (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Prepaid expenses and other current assets:
Prepaid expenses	$ 12,534		$ 12,534		$ 11,558
Unamortized cloud computing implementation costs	3,995		3,995		3,995
Prepaid insurance	995		995		521
Prepaid licenses and support	16,339		16,339		10,099
Prepaid expenses and other current assets	33,863		33,863		26,173
Other assets:
Unamortized cloud computing implementation costs	10,866		10,866		12,475
Other assets	2,897		2,897		3,538
Total other assets	13,763		13,763		16,013
Accrued expenses:
Accrued general expenses	20,472		20,472		25,998
Accrued contract labor and professional fees	18,344		18,344		13,372
Accrued income and other taxes	5,827		5,827		5,365
Accrued expenses	44,643		44,643		$ 44,735
Cloud computing implementation costs
Amortization expense for capitalized cloud computing implementation costs	$ 1,005	$ 919	$ 2,994	$ 1,550
Minimum
Cloud computing implementation costs
Capitalized software development cost amortization extension term			2 years
Maximum
Cloud computing implementation costs
Capitalized software development cost amortization extension term			5 years

REVENUE RECOGNITION - Disaggreg

REVENUE RECOGNITION - Disaggregation of revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Disaggregation of revenue:
Total revenues	$ 170,435	$ 145,027	$ 488,320	$ 417,473
Software subscriptions
Disaggregation of revenue:
Total revenues	146,254	121,285	414,527	350,135
Software licenses
Disaggregation of revenue:
Total revenues	75,273	66,637	215,365	196,070
Cloud subscriptions
Disaggregation of revenue:
Total revenues	70,981	54,648	199,162	154,065
Services
Disaggregation of revenue:
Total revenues	$ 24,181	$ 23,742	$ 73,793	$ 67,338

REVENUE RECOGNITION - Accounts

REVENUE RECOGNITION - Accounts receivable, net (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2024	Dec. 31, 2023	Jun. 30, 2024	Sep. 30, 2023	Jun. 30, 2023	Dec. 31, 2022
Accounts receivable
Allowance for accounts receivable	$ 14,273	$ 16,272	$ 17,704	$ 14,308	$ 14,218	$ 9,554
Balance, beginning of period	141,752	102,885
Balance, end of period	129,908	141,752
Increase (decrease), net	(11,844)	38,867
Software subscriptions
Accounts receivable
Allowance for accounts receivable	$ 14,273	$ 16,272

REVENUE RECOGNITION - Allowance

REVENUE RECOGNITION - Allowance and deferred allowance (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Allowance for credit loss
Beginning balance	$ (17,704)	$ (14,218)	$ (16,272)	$ (9,554)
Ending balance	(14,273)	(14,308)	(14,273)	(14,308)
Change in allowance	(3,431)	90	(1,999)	4,754
Deferred beginning balance	12,753	10,409	11,741	7,133
Deferred ending balance	10,235	10,472	10,235	10,472
Change in deferred allowance	2,518	(63)	1,506	(3,339)
Net amount charged to revenues	(913)	$ 27	(493)	$ 1,415
Software subscriptions
Allowance for credit loss
Beginning balance			(16,272)
Ending balance	(14,273)		(14,273)
Deferred beginning balance			11,741
Deferred ending balance	$ 10,235		$ 10,235

REVENUE RECOGNITION - Changes t

REVENUE RECOGNITION - Changes to deferred revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
REVENUE RECOGNITION
Beginning balance	$ 299,741	$ 277,053	$ 292,720	$ 279,136
Additional amounts deferred	175,106	134,789	500,012	405,152
Revenues recognized	(170,435)	(145,027)	(488,320)	(417,473)
Ending balance	$ 304,412	$ 266,815	$ 304,412	$ 266,815

REVENUE RECOGNITION - Contract

REVENUE RECOGNITION - Contract cost balances (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Deferred commissions:
Beginning balance	$ 21,862	$ 16,726	$ 21,237	$ 15,463
Additions	5,024	3,839	13,793	9,437
Amortization	(4,346)	(3,471)	(12,490)	(7,806)
Ending balance	$ 22,540	17,094	$ 22,540	17,094
Contract costs, amortization period	3 years		3 years
Impairment loss	$ 0	$ 0	$ 0	$ 0

ACQUISITIONS - Ecosio GmbH (Det

ACQUISITIONS - Ecosio GmbH (Details) $ in Thousands		3 Months Ended	9 Months Ended
	Aug. 30, 2024 USD ($) segment	Sep. 30, 2024 USD ($)	Sep. 30, 2024 USD ($) segment
Business combinations
Number of operating segment | segment			1
Ecosio
Business combinations
Equity interest acquired	100%
Number of operating segment | segment	1
Total purchase consideration, net of cash acquired	$ 169,041
Cash received in the acquisition	788
Initial cash consideration, net	$ 65,000
Target performance achievement, percentage	100%
Revenue performance target, term	3 years
Cash and Stock Earn-outs, at fair value	$ 105,000
Total transaction costs		$ 720	$ 1,637
Ecosio | Cash Earn-out
Business combinations
Maximum potential earnout payments	76,000
Cash and Stock Earn-outs, at fair value	71,000	71,000	71,000
Ecosio | Stock Earn-out
Business combinations
Maximum potential earnout payments	35,000
Cash and Stock Earn-outs, at fair value	$ 34,000	$ 34,000	$ 34,000

ACQUISITIONS - Purchase price (

ACQUISITIONS - Purchase price (Details) - Ecosio $ in Thousands	Aug. 30, 2024 USD ($)
Business combinations
Upfront cash consideration	$ 64,829
Cash and Stock Earn-outs, at fair value	105,000
Purchase price	$ 169,829

ACQUISITIONS - Net assets and l

ACQUISITIONS - Net assets and liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Aug. 30, 2024	Dec. 31, 2023
Business combinations
Goodwill	$ 382,449		$ 257,842
Ecosio
Business combinations
Cash and cash equivalents		$ 788
Accounts receivable		2,068
Prepaid expenses and other current assets		475
Property and equipment		63,984
Other assets		34
Goodwill		123,509
Other intangibles		5,950
Accounts payable		(1,118)
Third-party debt		(3,904)
Accrued expenses		(5,184)
Deferred revenue		(752)
Deferred income tax		(16,021)
Total		169,829
Ecosio | Developed technology
Business combinations
Property and equipment		$ 63,800

ACQUISITIONS - Intangible asset

ACQUISITIONS - Intangible assets acquired (Details) - Ecosio $ in Thousands	Aug. 30, 2024 USD ($)
Developed technology | Property and Equipment, net
Business combinations
Fair Value	$ 63,800
Estimated Useful Life	7 years
Discount Rate	15.50%
Trade Name | Goodwill and other intangible assets
Business combinations
Fair Value	$ 1,450
Estimated Useful Life	3 years
Discount Rate	15.50%
Customer relationships | Goodwill and other intangible assets
Business combinations
Fair Value	$ 4,500
Estimated Useful Life	3 years
Discount Rate	15.50%

ACQUISITIONS - Asset acquisitio

ACQUISITIONS - Asset acquisition (Details) - Ryan, LLC Artificial Intelligence Tax Categorization $ in Thousands	May 31, 2024 USD ($)
Asset Acquisition
Consideration paid	$ 6,075
Transaction costs	$ 75
Term for earnout payments and referral fees	5 years
Annual referral fees payment percentage	35%
Cloud-based customer solutions
Asset Acquisition
Weighted average amortization period (years)	5 years
Minimum
Asset Acquisition
Annual earnout payment percentage	0%
Maximum
Asset Acquisition
Annual earnout payment percentage	35%

FINANCIAL INSTRUMENTS AND FAI_3

FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS - Financial assets and liabilities measured at fair value (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Aug. 30, 2024	Dec. 31, 2023
Fair Value, Recurring
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Foreign Currency Forward Contracts			$ 849
Significant other observable inputs (Level 2) | Fair Value, Recurring
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Foreign Currency Forward Contracts			849
Money Market Funds | Fair Value, Recurring
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure	$ 249,150		53,049
Money Market Funds | Prices in active markets for identical assets (Level 1) | Fair Value, Recurring
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure	249,150		53,049
Commercial Paper | Fair Value, Recurring
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure	6,451		7,168
Commercial Paper | Significant other observable inputs (Level 2) | Fair Value, Recurring
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure	6,451		7,168
U.S. Treasury Securities | Fair Value, Recurring
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure	4,500		3,621
U.S. Treasury Securities | Significant other observable inputs (Level 2) | Fair Value, Recurring
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure	4,500		3,621
Tellutax
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Contingent consideration	300		4,900
Tellutax | Fair Value, Recurring
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Contingent consideration	300		4,900
Tellutax | Significant unobservable inputs (Level 3) | Fair Value, Recurring
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Contingent consideration	300		$ 4,900
Ecosio
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Contingent consideration		$ 105,000
Ecosio | Cash Earn-out
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Contingent consideration	71,000	71,000
Ecosio | Cash Earn-out | Fair Value, Recurring
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Contingent consideration	71,000
Ecosio | Cash Earn-out | Significant unobservable inputs (Level 3) | Fair Value, Recurring
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Contingent consideration	71,000
Ecosio | Stock Earn-out
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Contingent consideration	34,000	$ 34,000
Ecosio | Stock Earn-out | Fair Value, Recurring
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Contingent consideration	34,000
Ecosio | Stock Earn-out | Significant unobservable inputs (Level 3) | Fair Value, Recurring
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Contingent consideration	$ 34,000

FINANCIAL INSTRUMENTS AND FAI_4

FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS - Earn out consideration (Details) - Ecosio $ in Thousands	Aug. 30, 2024 USD ($) item	Sep. 30, 2024 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Number of potential earnout payments | item	3
Contingent consideration	$ 105,000
Cash Earn-out
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Maximum payout	76,000
Contingent consideration	71,000	$ 71,000
Stock Earn-out
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Maximum payout	35,000
Contingent consideration	34,000	$ 34,000
Year 1 - December 1, 2024 - December 1, 2025 | Cash Earn-out
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Maximum payout	16,000
Contingent consideration	16,700
Year 1 - December 1, 2024 - December 1, 2025 | Stock Earn-out
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Maximum payout	12,000
Contingent consideration	12,200
Year 2 - December 1, 2025 - December 1, 2026 | Cash Earn-out
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Maximum payout	25,000
Contingent consideration	23,200
Year 2 - December 1, 2025 - December 1, 2026 | Stock Earn-out
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Maximum payout	12,000
Contingent consideration	11,400
Year 3 - December 1, 2026 - December 1, 2027
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Maximum payout	35,000
Contingent consideration	31,100
Year 3 - December 1, 2026 - December 1, 2027 | Stock Earn-out
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Maximum payout	11,000
Contingent consideration	$ 10,400
If actual software revenues exceed 100% of the target
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Maximum additional earnout payment, percentage	122.50%
If actual software revenues are below 85% of the target
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Earnout payment	$ 0

FINANCIAL INSTRUMENTS AND FAI_5

FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS - Fair value of Cash and Stock Earn-outs (Details) - Ecosio $ in Thousands	Sep. 30, 2024 USD ($) Y	Aug. 30, 2024 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration		$ 105,000
Cash Earn-out
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration	$ 71,000	71,000
Cash Earn-out | Revenue volatility
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration measurement input	0.210
Cash Earn-out | Revenue discount rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration measurement input	0.076
Cash Earn-out | Term (in years)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration measurement input | Y	3
Stock Earn-out
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration	$ 34,000	$ 34,000
Stock Earn-out | Revenue volatility
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration measurement input	0.210
Stock Earn-out | Revenue discount rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration measurement input	0.076
Stock Earn-out | Term (in years)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration measurement input | Y	3

FINANCIAL INSTRUMENTS AND FAI_6

FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS - Estimated fair values of Tellutax contingent consideration (Details) $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended
	Jan. 31, 2021 USD ($) payment	Sep. 30, 2024 USD ($) Y	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($) Y	Sep. 30, 2023 USD ($)	Dec. 31, 2023 USD ($) Y
Fair Value Measurement Inputs and Valuation Techniques
Fair value adjustments to contingent consideration				$ (2,275)	$ 1,349
Purchase commitment and contingent consideration liabilities, current		$ 300		300		$ 11,901
Purchase commitment and contingent consideration liabilities, net of current portion		105,000		105,000		2,600
Tellutax
Fair Value Measurement Inputs and Valuation Techniques
Number of potential earnout payments | payment	3
Revenue achievement period	30 months
Earn out payment for applicable measurement period	$ 0
Maximum limit on earnout payments	$ 0
Contingent consideration		300		300		4,900
Fair value adjustments to contingent consideration		100	$ 900	(2,275)	$ 1,349
Purchase commitment and contingent consideration liabilities, current		$ 300		$ 300		2,300
Purchase commitment and contingent consideration liabilities, net of current portion						$ 2,600
Tellutax | Revenue volatility
Fair Value Measurement Inputs and Valuation Techniques
Contingent consideration measurement input		0.500		0.500		0.600
Tellutax | Revenue discount rate
Fair Value Measurement Inputs and Valuation Techniques
Contingent consideration measurement input		0.202		0.202		0.208
Tellutax | Term (in years)
Fair Value Measurement Inputs and Valuation Techniques
Contingent consideration measurement input | Y		0.6		0.6		1.3

FINANCIAL INSTRUMENTS AND FAI_7

FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS - Changes in fair value of contingent consideration (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2024 USD ($)
Cash Earn-out
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
ecosio acquisition (Note 3)	$ 71,000
Ending balance	71,000
Stock Earn-out
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
ecosio acquisition (Note 3)	34,000
Ending balance	34,000
Contingent consideration
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	4,900
Fair value adjustments	(2,275)
Payments	(2,325)
Ending balance	$ 300

FINANCIAL INSTRUMENTS AND FAI_8

FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS - Non-recurring Fair Value Measurements (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Jun. 05, 2024	Dec. 31, 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Adjustment in settlement value of deferred purchase commitment liability				$ (423)
Fair value of convertible senior notes	$ 428,418			428,418			$ 0
Systax
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Purchase commitment liability	12,592			$ 12,592
Adjustment in settlement value of deferred purchase commitment liability		$ (423)	$ 0		$ 0
Purchase price	$ 9,622
Equity interest acquired	20%			20%		20%
Purchase Commitment Liability							$ 9,601
Systax | Systax
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Ownership percentage	100%			100%

PROPERTY AND EQUIPMENT (Details

PROPERTY AND EQUIPMENT (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Property and equipment
Property and equipment	$ 381,328	$ 263,648
Less accumulated depreciation and amortization	(202,750)	(162,914)
Property and equipment, net	178,578	100,734
Leasehold improvements
Property and equipment
Property and equipment	20,673	20,662
Equipment
Property and equipment
Property and equipment	21,924	22,012
Computer software purchased
Property and equipment
Property and equipment	2,499	2,690
Internal-use software
Property and equipment
Property and equipment	305,261	181,732
Cloud-based customer solutions
Property and equipment
Property and equipment	237,638	142,302
Cloud-based customer solutions | Ecosio
Property and equipment
Property and equipment	63,984	63,984
Internal systems and tools
Property and equipment
Property and equipment	67,623	39,430
Furniture and fixtures
Property and equipment
Property and equipment	7,891	7,669
In-process internal-use software
Property and equipment
Property and equipment	$ 23,080	$ 28,883

PROPERTY AND EQUIPMENT - Additi

PROPERTY AND EQUIPMENT - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Property and equipment
Finance lease amortization	$ 19	$ 70	$ 61	$ 586
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, after Accumulated Depreciation and Amortization		Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, after Accumulated Depreciation and Amortization		Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, after Accumulated Depreciation and Amortization
Excluding internal-use software and capital leases
Property and equipment
Depreciation expense	$ 1,004	1,636	$ 3,369	5,260
Assets under finance leases
Property and equipment
Finance lease assets	172		172		$ 297
Accumulated amortization	78		78		$ 190
Cloud-based customer solutions
Property and equipment
Depreciation expense	7,909	8,821	25,685	25,230
Internal systems and tools
Property and equipment
Depreciation expense	$ 4,191	$ 1,466	$ 12,002	$ 5,695

PROPERTY AND EQUIPMENT - Major

PROPERTY AND EQUIPMENT - Major components of internal-use software (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Property and equipment
Property and equipment	$ 168,475	$ 88,969
Internal-use software
Property and equipment
Property and equipment, gross	305,261	181,732
Less accumulated depreciation	(159,866)	(121,646)
Internal-use software developed, net of accumulated depreciation	145,395	60,086
In-process internal-use software
Property and equipment
Property and equipment	$ 23,080	$ 28,883

PROPERTY AND EQUIPMENT - Amount

PROPERTY AND EQUIPMENT - Amounts included in property and equipment additions related to capitalized internal-use software (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Cloud-based customer solutions
Property and equipment
Total	$ 32,078	$ 22,170
Internal systems and tools
Property and equipment
Total	14,683	12,095
Internal-use software
Property and equipment
Total	$ 46,761	$ 34,265

CAPITALIZED SOFTWARE (Details)

CAPITALIZED SOFTWARE (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Capitalized software, movement
Capitalized software, net	$ 36,864		$ 36,864		$ 38,771
Capitalized software amortization expense	6,236	$ 5,147	18,264	$ 13,739
Software
Capitalized software, movement
Capitalized software, gross	134,615		134,615		115,152
Less accumulated amortization	(99,674)		(99,674)		(81,410)
Capitalized software, net	34,941		34,941		33,742
Capitalized development costs	5,260	$ 5,041	16,357	$ 14,083
In-process internal-use software
Capitalized software, movement
Capitalized software, gross	$ 1,924		$ 1,924		$ 5,029

GOODWILL AND OTHER INTANGIBLE_3

GOODWILL AND OTHER INTANGIBLE ASSETS (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Aug. 30, 2024	Dec. 31, 2023
Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 382,449		$ 257,842
Goodwill and other intangible assets	388,716		260,238
Ecosio
Finite-Lived Intangible Assets [Line Items]
Goodwill		$ 123,509
Other intangible assets
Finite-Lived Intangible Assets [Line Items]
Other intangible assets, net	6,267		$ 2,396
Other intangible assets | Ecosio
Finite-Lived Intangible Assets [Line Items]
Other intangible assets, net	$ 5,892

GOODWILL AND OTHER INTANGIBLE_4

GOODWILL AND OTHER INTANGIBLE ASSETS - Changes (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2024 USD ($)
GOODWILL AND OTHER INTANGIBLE ASSETS
Balance, January 1	$ 257,842
ecosio acquisition	123,509
Foreign currency translation adjustments	1,098
Balance, September 30, gross	382,449
Balance, September 30, net	$ 382,449

GOODWILL AND OTHER INTANGIBLE_5

GOODWILL AND OTHER INTANGIBLE ASSETS - Intangibles (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Amortization of acquired intangible assets
Amortization	$ 761	$ 657	$ 2,067	$ 2,227
Cost of Revenues
Amortization of acquired intangible assets
Amortization	55	61	174	181
Selling and marketing
Amortization of acquired intangible assets
Amortization	706	$ 596	$ 1,893	$ 2,046
Other intangible assets
Other intangible assets
Weighted average amortization period (years)			3 years 3 months 18 days		3 years 6 months
Gross Value	16,662		$ 16,662		$ 10,960
Accumulated amortization	(10,395)		(10,395)		(8,564)
Carrying Value	$ 6,267		$ 6,267		$ 2,396

DEBT - Credit Agreement (Detail

DEBT - Credit Agreement (Details) $ / shares in Units, $ in Thousands					3 Months Ended	9 Months Ended
	Jul. 01, 2024 D $ / shares	May 10, 2024 USD ($)	Apr. 26, 2024 USD ($) $ / shares	Apr. 23, 2024 USD ($) $ / shares shares	Jun. 30, 2024 USD ($)	Sep. 30, 2024 USD ($)
Debt
Proceeds from Convertible Debt						$ 345,000
Share price | $ / shares				$ 55.88
Purchase of capped calls					$ 31,517
Write-off of deferred financing costs						276
Capped call transaction
Debt
Anti-dilutive shares | shares				12,348
Purchase of capped calls				$ 42,366
Term Loan
Debt
Repaid Term Loan balance		$ 46,332
Interest included in repaid Term Loan balance		82
Write-off of deferred financing costs		$ 276
Convertible Senior Notes 7.50 Percent, Due 2029
Debt
Principal amount			$ 345,000
Debt instrument interest rate percentage			0.75%
Additional principal amount			$ 45,000
Trading days | D	20
Consecutive trading days | D	10
Threshold stock price percentage	130%
Conversion price | $ / shares	$ 47.21		$ 36.32
Convertible business days | D	5
Consecutive trading days | D	30
Percentage of stock price trigger	98%
Conversion rate			27.5315
Proceeds from Convertible Debt			$ 333,716
Cost of capped call transactions			$ 42,366
Line of Credit
Debt
Line of credit, capacity						200,000
New Term Loan
Debt
Principal amount						$ 50,000

DEBT - Indebtedness (Details)

DEBT - Indebtedness (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Debt
Principal Amount - Current		$ 2,500
Net Carrying Amount - Current		2,500
Principal Amount - Noncurrent		44,375
Discounts and Deferred Financing Costs - Noncurrent		(316)
Net Carrying Amount - Noncurrent	$ 334,656	44,059
Total debt -Principal Amount	345,000	46,875
Total Discounts and Deferred Financing Costs	(10,344)	(316)
Total Debt Net Carrying Amount	334,656	46,559
Term Loan
Debt
Principal Amount - Current		2,500
Net Carrying Amount - Current		2,500
Principal Amount - Noncurrent		44,375
Discounts and Deferred Financing Costs - Noncurrent		(316)
Net Carrying Amount - Noncurrent		$ 44,059
Convertible Notes
Debt
Total debt -Principal Amount	345,000
Total Discounts and Deferred Financing Costs	(10,344)
Total Debt Net Carrying Amount	$ 334,656

DEBT - Interest expense related

DEBT - Interest expense related to Notes (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2024	Sep. 30, 2023
Debt Instrument [Line Items]
Amortization of deferred financing costs		$ 1,345	$ 189
Convertible Senior Notes 7.50 Percent, Due 2029
Debt Instrument [Line Items]
Contractual interest expense	$ 677	1,108
Amortization of deferred financing costs	564	940
Total interest expense	$ 1,241	$ 2,048

STOCKHOLDERS EQUITY (Details)

STOCKHOLDERS EQUITY (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Class A
Common Stock
Exercise of stock options, net (in shares)	461	744	1,308	1,595
Shares exchanged	2	292	268	315
Class A | Restricted Stock Units
Common Stock
Shares issued upon vesting of Restricted Stock Units, net (in shares)	74	56	780	469
Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation	36	24	467	266
Class A | Restricted Stock Awards
Common Stock
Shares issued upon vesting of Restricted Stock Units, net (in shares)	22	92	84	198
Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation	7	7	7	7
Class A | ESPP
Common Stock
Shares issued upon vesting of Restricted Stock Units, net (in shares)			61	81
Class B
Common Stock
Exchange of shares		879	2,500	3,468

EARNINGS PER SHARE (Details)

EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Class A
Numerator:
Allocation of net income (loss), basic	$ 3,038	$ (1,228)	$ 6,197	$ (9,960)
Total net income (loss) used in per diluted computation	$ 3,206	$ (1,228)	$ 6,549	$ (9,960)
Denominator:
Total shares used in per share computation, basic (in shares)	65,468	54,931	63,742	53,050
Dilutive effect of common stock equivalents	6,509		6,394
Total shares used in per share computation, diluted (in shares)	71,977	54,931	70,136	53,050
Basic net income (loss) per share: (in dollars per share)	$ 0.05	$ (0.02)	$ 0.10	$ (0.19)
Dilutive net income (loss) per share: (in dollars per share)	$ 0.04	$ (0.02)	$ 0.09	$ (0.19)
Class B
Numerator:
Allocation of net income (loss), basic	$ 4,183	$ (2,171)	$ 8,872	$ (18,467)
Total net income (loss) used in per diluted computation	$ 4,015	$ (2,171)	$ 8,520	$ (18,467)
Denominator:
Total shares used in per share computation, basic (in shares)	90,161	97,145	91,251	98,361
Total shares used in per share computation, diluted (in shares)	90,161	97,145	91,251	98,361
Basic net income (loss) per share: (in dollars per share)	$ 0.05	$ (0.02)	$ 0.10	$ (0.19)
Dilutive net income (loss) per share: (in dollars per share)	$ 0.04	$ (0.02)	$ 0.09	$ (0.19)

EARNINGS PER SHARE - weighted-

EARNINGS PER SHARE - weighted- Average outstanding shares of common stock equivalents (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Employee Stock Option
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares		7,025		7,316
Stock Options out-of-the money options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares		307	135	498
RSAs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares		121		193
RSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares		4,162		3,825
ESPP
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares		36		43
Convertible Senior Notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares	8,194		5,462

STOCK-BASED AWARD PLANS - 2020

STOCK-BASED AWARD PLANS - 2020 Plan (Details) shares in Thousands	Sep. 30, 2024 shares
Employee Stock Option
Compensation plans:
Shares authorized	20,857

STOCK-BASED AWARD PLANS - Optio

STOCK-BASED AWARD PLANS - Options under 2020 Plan (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Weighted Average Per Share
Unrecognized compensation expense period			9 months 18 days
Employee Stock Option
Units
Beginning, balance			5,692
Granted	0	0	0	0
Exercised			(1,576)
Ending balance	4,116		4,116		5,692
Exercisable	3,006		3,006
Weighted Average Per Share
Beginning balance			$ 5.32
Exercised			3.77
Ending Balance	$ 5.91		5.91		$ 5.32
Exercisable	$ 5.48		$ 5.48
Remaining contractual life, outstanding			4 years 4 months 24 days		4 years 8 months 12 days
Remaining contractual life, exercisable			3 years 10 months 24 days
Intrinsic value, outstanding	$ 134,178		$ 134,178		$ 124,327
Intrinsic value, exercisable	99,287		99,287
Unrecognized compensation cost	$ 1,528		$ 1,528
Employee Stock Option | Minimum
Weighted Average Per Share
Vesting period			1 year
Employee Stock Option | Maximum
Weighted Average Per Share
Vesting period			4 years

STOCK-BASED AWARD PLANS - Opt_2

STOCK-BASED AWARD PLANS - Options under 2020 Plan Price Range (Details) - Employee Stock Option shares in Thousands	9 Months Ended
	Sep. 30, 2024 $ / shares shares
Options outstanding, vested and exercisable:
Options outstanding	4,116
Options vested and exercisable	3,006
$0.15 to $0.71
Options outstanding, vested and exercisable:
Exercise prices, lower range | $ / shares	$ 0.15
Exercise prices, upper range | $ / shares	$ 0.71
Options outstanding	725
Options outstanding, life	0 years
Options vested and exercisable	725
Options vested and exercisable, life	0 years
$2.50
Options outstanding, vested and exercisable:
Exercise prices | $ / shares	$ 2.50
Options outstanding	1,019
Options outstanding, life	1 year 10 months 24 days
Options vested and exercisable	1,019
Options vested and exercisable, life	1 year 10 months 24 days
$3.17
Options outstanding, vested and exercisable:
Exercise prices | $ / shares	$ 3.17
Options outstanding	217
Options outstanding, life	3 years 7 months 6 days
Options vested and exercisable	217
Options vested and exercisable, life	3 years 7 months 6 days
$3.73
Options outstanding, vested and exercisable:
Exercise prices | $ / shares	$ 3.73
Options outstanding	1,004
Options outstanding, life	5 years 1 month 6 days
Options vested and exercisable	412
Options vested and exercisable, life	5 years
$4.70
Options outstanding, vested and exercisable:
Exercise prices | $ / shares	$ 4.70
Options outstanding	541
Options outstanding, life	5 years 4 months 24 days
Options vested and exercisable	200
Options vested and exercisable, life	5 years 4 months 24 days
$18.47
Options outstanding, vested and exercisable:
Exercise prices | $ / shares	$ 18.47
Options outstanding	213
Options outstanding, life	7 years 2 months 12 days
Options vested and exercisable	107
Options vested and exercisable, life	7 years 2 months 12 days
$18.96
Options outstanding, vested and exercisable:
Exercise prices | $ / shares	$ 18.96
Options outstanding	110
Options outstanding, life	6 years 10 months 24 days
Options vested and exercisable	110
Options vested and exercisable, life	6 years 10 months 24 days
$19.00
Options outstanding, vested and exercisable:
Exercise prices | $ / shares	$ 19
Options outstanding	47
Options outstanding, life	7 years
Options vested and exercisable	31
Options vested and exercisable, life	7 years
$32.16
Options outstanding, vested and exercisable:
Exercise prices | $ / shares	$ 32.16
Options outstanding	240
Options outstanding, life	6 years 4 months 24 days
Options vested and exercisable	185
Options vested and exercisable, life	6 years 4 months 24 days

STOCK-BASED AWARD PLANS - Restr

STOCK-BASED AWARD PLANS - Restricted Stock Units (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	9 Months Ended
	Sep. 30, 2024
Weighted Average Per Share
Unrecognized compensation expense period	9 months 18 days
Restricted Stock Units
Units
Beginning balance (in units)	4,171
Granted (in units)	1,793
Vested (in units)	(1,247)
Forfeited (in units)	(119)
Ending balance (in units)	4,598
Weighted Average Per Share
Beginning balance (in dollars per share)	$ 16.11
Granted (in dollars per share)	25.73
Vested (in dollars per share)	16.38
Forfeited (in dollars per share)	16.42
Ending balance (in dollars per share)	$ 19.77
Unrecognized compensation cost	$ 60,882
Unrecognized compensation expense period	2 years 6 months
Restricted Stock Units | Minimum
Compensation plans:
Service requirement (in years)	1 year
Restricted Stock Units | Maximum
Compensation plans:
Service requirement (in years)	4 years

STOCK-BASED AWARD PLANS - Res_2

STOCK-BASED AWARD PLANS - Restricted Stock Awards (Details) $ / shares in Units, shares in Thousands, $ in Thousands	9 Months Ended
	Sep. 30, 2024 USD ($) $ / shares shares
Weighted Average Per Share
Unrecognized compensation expense period	9 months 18 days
Restricted Stock Awards
Units
Beginning balance (in units) | shares	91
Granted (in units) | shares	34
Vested (in units) | shares	(91)
Ending balance (in units) | shares	34
Weighted Average Per Share
Beginning balance (in dollars per share) | $ / shares	$ 21.50
Granted (in dollars per share) | $ / shares	35.06
Vested (in dollars per share) | $ / shares	21.50
Ending balance (in dollars per share) | $ / shares	$ 35.06
Unrecognized compensation cost | $	$ 836
Unrecognized compensation expense period	9 months 18 days
Restricted Stock Awards | Minimum
Compensation plans:
Service requirement (in years)	1 year
Restricted Stock Awards | Maximum
Compensation plans:
Service requirement (in years)	4 years

STOCK-BASED AWARD PLANS - Emplo

STOCK-BASED AWARD PLANS - Employee Stock Purchase Plan (Details) shares in Thousands, $ in Thousands	9 Months Ended
	Sep. 30, 2024 USD ($) period shares	Sep. 30, 2023 period
Class A
Compensation plans:
Purchase price as a percent of fair value	85%
ESPP
Compensation plans:
Reserved for issuance | shares	6,390
Amounts withheld from participants	$ 1,259
Unrecognized compensation cost	$ 175
Number of offering periods | period	2	2
ESPP offering period	6 months
Discount	15%	15%

STOCK-BASED AWARD PLANS - ESPP

STOCK-BASED AWARD PLANS - ESPP - Option-pricing model key input assumptions (Details) - Initial Public Offering - ESPP - $ / shares	1 Months Ended
	Nov. 30, 2024	Nov. 30, 2023
Fair Value Assumptions and Methodology
Fair market value of common stock	$ 33.26	$ 21.76
Volatility	41.70%	39.40%
Expected term (in years)	6 months	6 months
Risk-free interest rate	5.40%	5.40%

STOCK-BASED AWARD PLANS - Stock

STOCK-BASED AWARD PLANS - Stock based compensation (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Allocation of costs
Compensation expense	$ 10,134	$ 7,772	$ 36,459	$ 26,228
Employee Stock Option
Allocation of costs
Compensation expense	1,219	1,515	4,969	4,788
Restricted Stock Units
Allocation of costs
Compensation expense	8,305	5,452	29,453	18,762
Restricted Stock Awards
Allocation of costs
Compensation expense	347	598	1,313	2,076
ESPP
Allocation of costs
Compensation expense	$ 263	$ 207	$ 724	$ 602

STOCK-BASED AWARD PLANS - Sto_2

STOCK-BASED AWARD PLANS - Stock based compensation, comprehensive loss (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Allocation of costs
Compensation expense	$ 10,134	$ 7,772	$ 36,459	$ 26,228
Software subscriptions
Allocation of costs
Compensation expense	894	728	3,437	2,143
Services
Allocation of costs
Compensation expense	558	452	2,129	1,454
Research and development
Allocation of costs
Compensation expense	2,001	1,398	7,296	4,407
Selling and marketing
Allocation of costs
Compensation expense	2,951	2,325	10,101	6,305
General and administrative
Allocation of costs
Compensation expense	$ 3,730	$ 2,869	$ 13,496	$ 11,919

INCOME TAXES - (Details)

INCOME TAXES - (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
INCOME TAXES
Income tax (benefit) expense	$ 613	$ 784	$ (1,722)	$ 13,266
Effective tax rate (as a percent)	7.80%	(30.00%)	(12.90%)	(87.50%)
U.S. federal statutory income tax rate	21%	21%	21%	21%

SUBSEQUENT EVENTS (Details)

SUBSEQUENT EVENTS (Details) - Line of Credit - USD ($)	Nov. 04, 2024	Nov. 03, 2024	Sep. 30, 2024
Subsequent events:
Line of credit, capacity			$ 200,000,000
Subsequent event
Subsequent events:
Line of credit, capacity	$ 300,000	$ 200,000