Calix (CALX) 10-Q 23 Apr 24 2024 Q1 Quarterly report Financial data

Cover

Cover - shares	3 Months Ended
	Mar. 30, 2024	Apr. 15, 2024
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 30, 2024
Document Transition Report	false
Entity File Number	001-34674
Entity Registrant Name	Calix, Inc
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	68-0438710
Entity Address, Address Line One	2777 Orchard Parkway
Entity Address, City or Town	San Jose
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	95134
City Area Code	408
Local Phone Number	514-3000
Title of 12(b) Security	Common Stock, par value $0.025 per share
Trading Symbol	CALX
Security Exchange Name	NYSE
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 Common Stock, Shares Outstanding		65,525,049
Entity Central Index Key	0001406666
Amendment Flag	false
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q1
Current Fiscal Year End Date	--12-31

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 30, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 88,418	$ 63,409
Marketable securities	151,064	156,937
Accounts receivable, net	100,307	126,027
Inventory	119,782	132,985
Prepaid expenses and other current assets	119,214	118,598
Total current assets	578,785	597,956
Property and equipment, net	28,876	29,461
Right-of-use operating leases	9,065	9,262
Deferred tax assets	170,213	167,691
Goodwill	116,175	116,175
Other assets	19,674	21,320
Total assets	922,788	941,865
Current liabilities:
Accounts payable	19,026	34,746
Accrued liabilities	87,605	116,227
Deferred revenue	39,448	36,669
Total current liabilities	146,079	187,642
Long-term portion of deferred revenue	24,434	24,864
Operating leases	6,925	7,421
Other long-term liabilities	2,657	2,956
Total liabilities	180,095	222,883
Commitments and contingencies (See Note 6)
Stockholders’ equity:
Preferred stock, $0.025 par value; 5,000 shares authorized; no shares issued and outstanding as of March 30, 2024 and December 31, 2023	0	0
Common stock, $0.025 par value; 100,000 shares authorized; 65,525 shares issued and outstanding as of March 30, 2024, and 65,052 shares issued and outstanding as of December 31, 2023	1,638	1,627
Additional paid-in capital	1,102,314	1,078,393
Accumulated other comprehensive loss	(983)	(659)
Accumulated deficit	(360,276)	(360,379)
Total stockholders’ equity	742,693	718,982
Total liabilities and stockholders’ equity	$ 922,788	$ 941,865

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Mar. 30, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.025	$ 0.025
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.025	$ 0.025
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	65,525,000	65,052,000
Common stock, shares outstanding (in shares)	65,525,000	65,052,000

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 30, 2024	Apr. 01, 2023
Income Statement [Abstract]
Revenue	$ 226,310	$ 250,008
Cost of revenue	103,733	121,957
Gross profit	122,577	128,051
Operating expenses:
Sales and marketing	53,897	51,865
Research and development	44,422	43,173
General and administrative	26,290	23,077
Total operating expenses	124,609	118,115
Operating income (loss)	(2,032)	9,936
Interest income and other expense, net:
Interest income, net	2,635	1,640
Other expense, net	(135)	(167)
Total interest income and other expense, net	2,500	1,473
Income before income taxes	468	11,409
Income taxes	365	1,811
Net income	$ 103	$ 9,598
Net income per common share:
Basic (in dollars per share)	$ 0	$ 0.15
Diluted (in dollars per share)	$ 0	$ 0.14
Weighted-average number of shares used to compute net income per common share:
Basic (in shares)	65,338	66,044
Diluted (in shares)	68,119	69,708
Net income	$ 103	$ 9,598
Other comprehensive income (loss), net of tax:
Unrealized gain (loss) on available-for-sale marketable securities, net	(212)	1,064
Foreign currency translation adjustments, net	(112)	102
Total other comprehensive income (loss), net of tax	(324)	1,166
Comprehensive income (loss)	$ (221)	$ 10,764

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit
Beginning Balance (in shares) at Dec. 31, 2022		65,735
Balance at beginning of period at Dec. 31, 2022	$ 679,567	$ 1,644	$ 1,070,100	$ (2,473)	$ (389,704)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	16,220		16,220
Issuance of common stock under equity incentive plans, net of forfeitures (in shares)		534
Issuance of common stock under equity incentive plans, net of forfeitures	12,471	$ 13	12,458
Repurchases of common stock (in shares)		(25)
Repurchases of common stock	(1,183)	$ (1)	(1,182)
Net income	9,598				9,598
Other comprehensive income (loss)	1,166			1,166
Ending Balance (in shares) at Apr. 01, 2023		66,244
Balance at end of period at Apr. 01, 2023	$ 717,839	$ 1,656	1,097,596	(1,307)	(380,106)
Beginning Balance (in shares) at Dec. 31, 2023	65,052	65,052
Balance at beginning of period at Dec. 31, 2023	$ 718,982	$ 1,627	1,078,393	(659)	(360,379)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	16,856		16,856
Issuance of common stock under equity incentive plans, net of forfeitures (in shares)		587
Issuance of common stock under equity incentive plans, net of forfeitures	$ 10,814	$ 14	10,800
Repurchases of common stock (in shares)	(100)	(114)
Repurchases of common stock	$ (3,738)	$ (3)	(3,735)
Net income	103				103
Other comprehensive income (loss)	$ (324)			(324)
Ending Balance (in shares) at Mar. 30, 2024	65,525	65,525
Balance at end of period at Mar. 30, 2024	$ 742,693	$ 1,638	$ 1,102,314	$ (983)	$ (360,276)

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 30, 2024	Apr. 01, 2023
Operating activities:
Net income	$ 103	$ 9,598
Adjustments to reconcile net income to net cash provided by operating activities:
Stock-based compensation	16,856	16,220
Depreciation and amortization	4,867	3,723
Deferred income taxes	(2,448)	(681)
Net accretion of available-for-sale securities	(1,406)	(708)
Changes in operating assets and liabilities:
Accounts receivable, net	25,719	1,595
Inventory	13,203	(7,353)
Prepaid expenses and other assets	272	(7,083)
Accounts payable	(15,973)	(5,899)
Accrued liabilities	(28,056)	(8,688)
Deferred revenue	2,348	11,005
Other long-term liabilities	(794)	(3,617)
Net cash provided by operating activities	14,691	8,112
Investing activities
Purchases of property and equipment	(3,709)	(4,618)
Purchases of marketable securities	(35,575)	(54,908)
Maturities of marketable securities	42,565	56,248
Net cash provided by (used in) investing activities	3,281	(3,278)
Financing activities:
Proceeds from common stock issuances related to employee benefit plans	10,814	12,471
Repurchases of common stock	(3,738)	(1,183)
Payments related to financing arrangements	0	(1,066)
Net cash provided by financing activities	7,076	10,222
Effect of exchange rate changes on cash and cash equivalents	(39)	57
Net increase in cash and cash equivalents	25,009	15,113
Cash and cash equivalents at beginning of period	63,409	79,073
Cash and cash equivalents at end of period	$ 88,418	$ 94,186

Company and Basis of Presentati

Company and Basis of Presentation	3 Months Ended
	Mar. 30, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Company and Basis of Presentation	Company and Basis of Presentation Company Calix, Inc. (together with its subsidiaries, “Calix” or the “Company”) was incorporated in August 1999 and is a Delaware corporation. The Company is the leading global provider of a platform (cloud, software and systems) and managed services that focus on the subscriber-facing network, the portion of the network that governs available bandwidth and determines the range and quality of services that can be offered to subscribers. This platform and managed services enable broadband service providers (“BSPs”) of all sizes to innovate and transform their businesses. The Company’s BSP customers are empowered to utilize real-time data and insights from the Calix platform to simplify their businesses and deliver experiences that excite their subscribers. These insights enable BSPs to grow their businesses through increased subscriber acquisition, loyalty and revenue, thereby increasing the value of their businesses and contributions to their communities. Basis of Presentation The accompanying unaudited condensed consolidated financial statements, including the accounts of Calix, Inc. and its wholly-owned subsidiaries, have been prepared in accordance with the requirements of the U.S. Securities and Exchange Commission (“SEC”) for interim reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by U.S. generally accepted accounting principles (“GAAP”) can be condensed or omitted. In the opinion of management, the financial statements include all normal and recurring adjustments that are considered necessary for the fair presentation of the Company’s financial position and operating results. All intercompany balances and transactions have been eliminated in consolidation. The Condensed Consolidated Balance Sheet as of December 31, 2023 has been derived from the audited financial statements at that date. The results of the Company’s operations can vary during each quarter of the year. Therefore, the results and trends in these interim financial statements may not be the same as those for the full year or any future periods. The information included in this Quarterly Report on Form 10-Q should be read in conjunction with the audited financial statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2023. The Company’s fiscal year begins on January 1 st and ends on December 31 st . Quarterly periods are based on a 4-4-5 calendar with the first quarter ending on the Saturday closest to March 31 st . As a result, the Company had one less day in the three months ended March 30, 2024 than for the three months ended April 1, 2023. The preparation of financial statements in conformity with GAAP for interim financial reporting requires management to make estimates and assumptions that affect the amounts reported in the condensed consolidated financial statements and accompanying notes. Actual results could differ from those estimates.

Significant Accounting Policies

Significant Accounting Policies	3 Months Ended
	Mar. 30, 2024
Accounting Policies [Abstract]
Significant Accounting Policies	Significant Accounting Policies The Company’s significant accounting policies are disclosed in its Annual Report on Form 10-K for the year ended December 31, 2023. The Company’s significant accounting policies did not change during the three months ended March 30, 2024. Newly Adopted Accounting Standard The Company did not adopt any new accounting standards during the three months ended March 30, 2024 that were significant to the Company. Recent Accounting Pronouncements Not Yet Adopted There have been no additional accounting pronouncements or changes in accounting pronouncements during the three months ended March 30, 2024 as compared to the recent accounting pronouncements described in the Company’s Annual Report on Form 10-K for the year ended December 31, 2023, that are significant or expected to be significant to the Company.

Cash, Cash Equivalents and Mark

Cash, Cash Equivalents and Marketable Securities	3 Months Ended
	Mar. 30, 2024
Cash and Cash Equivalents [Abstract]
Cash, Cash Equivalents and Marketable Securities	Cash, Cash Equivalents and Marketable Securities The Company has invested its excess cash primarily in money market funds and highly liquid marketable securities such as U.S. treasury securities, corporate debt instruments, commercial paper and U.S. government securities. The Company considers all investments with maturities of three months or less when purchased to be cash equivalents. Marketable securities represent highly liquid U.S. treasury securities, corporate debt instruments, commercial paper and U.S. government securities with maturities greater than 90 days at date of purchase. Cash equivalents are stated at amounts that approximate fair value based on quoted market prices. Marketable securities are recorded at their fair values. Marketable securities with maturities greater than one year are classified as current because management considers all marketable securities to be available for current operations. The Company’s investments have been classified and accounted for as available-for-sale. Such investments are recorded at fair value and unrealized holding gains and losses are reported as a separate component of accumulated other comprehensive loss in stockholders’ equity until realized. Realized gains and losses on sales of marketable securities, if any, are determined on the specific identification method and are reclassified from accumulated other comprehensive loss to results of operations as other expense, net. There were no realized gains and losses for each of the three months ended March 30, 2024 and April 1, 2023. Cash, cash equivalents and marketable securities consisted of the following (in thousands): March 30, December 31, Cash and cash equivalents: Cash $ 34,063 $ 18,040 Commercial paper 28,704 32,837 Money market funds 21,556 2,563 U.S. government securities 3,098 9,969 U.S. government agency securities 997 — Total cash and cash equivalents 88,418 63,409 Marketable securities: U.S. government securities 83,412 92,277 U.S. government agency securities 40,287 43,521 Commercial paper 20,366 14,139 Corporate debt securities 6,999 7,000 Municipal securities — — Total marketable securities 151,064 156,937 $ 239,482 $ 220,346 The carrying amounts of the Company’s money market funds approximate their fair values due to their nature, duration and short maturities. The amortized cost and fair value of marketable securities were as follows (in thousands): As of March 30, 2024 Amortized Cost Unrealized Losses Fair Value U.S. government securities $ 86,588 $ (78) $ 86,510 Commercial paper 49,092 (22) 49,070 U.S. government agency securities 41,439 (155) 41,284 Corporate debt securities 7,027 (28) 6,999 $ 184,146 $ (283) $ 183,863 As of December 31, 2023 Amortized Cost Unrealized Losses Fair Value U.S. government securities $ 102,167 $ 80 $ 102,247 Commercial paper 47,003 (28) 46,975 U.S. government agency securities 43,573 (52) 43,521 Corporate debt securities 6,999 1 7,000 $ 199,742 $ 1 $ 199,743

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 30, 2024
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The Company measures its cash equivalents and marketable securities at fair value on a recurring basis. Fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. The Company utilizes the following three-tier value hierarchy, which prioritizes the inputs used in measuring fair value: Level 1 – Observable inputs that reflect quoted prices (unadjusted) for identical assets or liabilities in active markets. Level 2 – Observable inputs other than quoted prices included in Level 1 for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, and model-driven valuations in which all significant inputs and significant value drivers are observable in active markets. Level 3 – Unobservable inputs to the valuation derived from fair valuation techniques in which one or more significant inputs or significant value drivers are unobservable. The fair value hierarchy also requires the Company to maximize the use of observable inputs, when available, and to minimize the use of unobservable inputs when determining inputs and determining fair value. The following tables sets forth the Company’s financial assets measured at fair value on a recurring basis based on the three-tier fair value hierarchy (in thousands): As of March 30, 2024 Level 1 Level 2 Total Money market funds $ 21,556 $ — $ 21,556 U.S. government securities 86,510 — 86,510 Commercial paper — 49,070 49,070 U.S. government agency securities — 41,284 41,284 Corporate debt securities — 6,999 6,999 $ 108,066 $ 97,353 $ 205,419 As of December 31, 2023 Level 1 Level 2 Total Money market funds $ 2,563 $ — $ 2,563 U.S. government securities 102,246 — 102,246 Commercial paper — 46,976 46,976 U.S. government agency securities — 43,521 43,521 Corporate debt securities — 7,000 7,000 $ 104,809 $ 97,497 $ 202,306

Balance Sheet Details

Balance Sheet Details	3 Months Ended
	Mar. 30, 2024
Balance Sheet Related Disclosures [Abstract]
Balance Sheet Details	Balance Sheet Details Accounts receivable, net consisted of the following (in thousands): March 30, December 31, Accounts receivable $ 100,617 $ 126,331 Allowance for doubtful accounts (310) (304) $ 100,307 $ 126,027 Inventory consisted of the following (in thousands): March 30, December 31, Raw materials $ 25,675 $ 22,119 Finished goods 94,107 110,866 $ 119,782 $ 132,985 Prepaid expenses and other current assets consisted of the following (in thousands): March 30, December 31, Supplier deposits $ 76,131 $ 78,131 Prepaid expenses and other current assets 43,083 40,467 $ 119,214 $ 118,598 Property and equipment, net consisted of the following (in thousands): March 30, December 31, Test equipment $ 52,838 $ 50,853 Computer equipment 14,008 13,615 Software 10,534 12,972 Leasehold improvements 2,107 2,122 Furniture and fixtures 1,267 1,283 Total 80,754 80,845 Accumulated depreciation and amortization (51,878) (51,384) $ 28,876 $ 29,461 Accrued liabilities consisted of the following (in thousands): March 30, December 31, Component inventory held by suppliers $ 25,536 $ 32,182 Compensation and related benefits 22,630 36,741 Professional and consulting fees 6,985 7,717 Current portion of warranty and retrofit 5,581 5,655 Operating leases 4,236 4,142 Taxes payable 4,165 4,317 Litigation settlement 3,250 3,250 Product returns 3,040 2,897 Customer advances or rebates 3,038 5,967 Insurance 2,106 2,107 Business events — 2,938 Other 7,038 8,314 $ 87,605 $ 116,227 Changes in the Company’s accrued warranty and retrofit liability were as follows (in thousands): Three Months Ended March 30, April 1, Balance at beginning of period $ 8,029 $ 8,386 Accruals for product warranty and retrofit 339 1,016 Cost of warranty and retrofit claims (713) (957) Balance at end of period $ 7,655 $ 8,445

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 30, 2024
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Lease Commitments The Company leases office space under non-cancelable operating leases. Certain of the Company’s operating leases contain renewal options and rent acceleration clauses. Future minimum payments under the non-cancelable operating leases consisted of the following as of March 30, 2024 (in thousands): Period Future Minimum Lease Payments Remainder of 2024 $ 3,522 2025 4,545 2026 1,672 2027 1,240 2028 and thereafter 1,048 Total future minimum lease payments 12,027 Less imputed interest (866) $ 11,161 As of March 30, 2024, the operating lease liability consisted of the following (in thousands): Accrued liabilities - current portion of operating leases $ 4,236 Operating leases 6,925 $ 11,161 The Company leases its headquarters office space in San Jose, California under a lease agreement that expires in December 2025. The future minimum lease payments under the lease are $4.3 million and are included in the table above. The weighted average discount rate for the Company’s operating leases as of March 30, 2024 was 5.1%. The weighted average remaining lease term as of March 30, 2024 was 3.1 years. For the three months ended March 30, 2024 and April 1, 2023, total rent expense of the Company was $1.1 million and $1.2 million, respectively. Cash paid within operating cash flows for operating leases was $1.1 million and $1.2 million for the three months ended March 30, 2024 and April 1, 2023, respectively. Purchase Commitments The Company’s contract manufacturers (“CMs”) and original design manufacturers (“ODMs”) place orders for component inventory based upon the Company’s build forecasts and pursuant to stated component lead times to ensure adequate component supply. The components are used by the CMs and ODMs to build the products included in the build forecasts. The Company generally does not take ownership of the components held by CMs and ODMs. The Company places purchase orders with its CMs and ODMs in order to fulfill its monthly finished product inventory requirements. The Company incurs a liability when it takes ownership of the finished goods inventory after the CMs and ODMs convert the component inventory into a finished product. The Company has from time to time, and subject to certain conditions, reimbursed certain suppliers for component inventory purchases when this inventory has been rendered excess or obsolete, for example due to manufacturing and engineering change orders resulting from design changes, manufacturing discontinuation of products by its suppliers, or in cases where the Company has committed inventory levels that greatly exceed actual demand. In the event of termination of services with a manufacturing partner, the Company has purchased, and may be required to purchase in the future, certain of the remaining components inventory held by the CM or ODM as well as any outstanding orders pursuant to the contractual provisions with such CM or ODM. The estimated excess and obsolete component liabilities related to manufacturing and engineering change orders, termination of manufacturing partners and other factors are included in “Accrued liabilities” in the accompanying Condensed Consolidated Balance Sheets, because the corresponding component parts have not been received by the Company. The Company records the related charges in “Cost of revenue” in its Condensed Consolidated Statements of Comprehensive Income (Loss). As of March 30, 2024 and December 31, 2023, the Company had approximately $146.8 million and $176.3 million, respectively, of outstanding purchase commitments for inventories to be delivered by its suppliers, including CMs and ODMs. Litigation From time to time, the Company is involved in various legal proceedings arising from the normal course of business activities. The Company is not currently a party to any legal proceeding or any legal proceeding known to be contemplated by government authorities that, if determined adversely to the Company, in management’s opinion, is currently expected to individually or in the aggregate have a material adverse effect on the Company’s business, operating results or financial condition taken as a whole.

Stockholders' Equity

Stockholders' Equity	3 Months Ended
	Mar. 30, 2024
Equity [Abstract]
Stockholders' Equity	Stockholders’ Equity 2019 Equity Incentive Award Plan Employees and consultants of the Company, its subsidiaries and affiliates, as well as members of the Company’s Board of Directors, are eligible to receive awards under the 2019 Equity Incentive Award Plan (the “2019 Plan”). The 2019 Plan provides for the grant of stock options, including incentive stock options and nonqualified stock options, stock appreciation rights, restricted stock, restricted stock units, other stock or cash-based awards and dividend equivalents to eligible individuals. As of March 30, 2024, there were 2.9 million shares available for issuance under the 2019 Plan. During the three months ended March 30, 2024, time-based stock option awards exercisable for up to an aggregate of 0.3 million shares of common stock were granted with a grant date weighted-average exercise price of $35.95 per share. These stock option awards vest 25% on the first anniversary of the vesting commencement date and on a quarterly basis thereafter over an additional three years. In February 2024, performance-based stock option awards exercisable for up to an aggregate of 2.4 million shares of common stock were granted to certain Company executives with a grant date exercise price of $34.26 per share and divided into two plans, with the first plan accounting for 75% of the total shares granted and the second plan accounting for 25% of the total shares granted. The actual number of shares earned is contingent upon achievement of annual corporate financial targets for bookings and non-GAAP net operating income for 2024 (collectively, the “2024 Performance Targets”) during the one-year performance period. These performance-based stock option awards will vest, subject to certification by the Compensation Committee of the Company’s Board of Directors upon the achievement of the 2024 Performance Targets, as to 25% of the shares of common stock earned on the one year anniversary of the date of grant, and as to the remaining 75% of the shares of common stock earned, in substantially equal quarterly installments over the subsequent 36 months, subject to the executive’s continuous service with the Company through the respective vesting dates. For the first plan, if the non-GAAP net operating income target and the bookings target are each achieved below 80% of target, no shares would be awarded, and the performance-based stock option awards would be forfeited in full. If either target is achieved at the minimum threshold of 80% of target, then the shares are awarded at 75% of the granted shares, with an increasing percentage of shares awarded above the minimum thresholds up to 120% of the granted shares for each target. Each target result is then weighted by 50% and the combined total determines the percent of target shares. The maximum combined award is 100%. For the second plan, if the bookings target is achieved below 90% of target, the performance-based stock option awards would be forfeited in full. If the target is achieved at the minimum threshold of 90% of target, then the shares are awarded at 75% with an increasing percentage of shares awarded above the minimum thresholds up to 100% of the granted shares. The maximum award is 100%. The probability of meeting a portion of the performance conditions related to these performance-based stock option awards was assessed to be probable as of March 30, 2024, and stock-based compensation expense of $1.7 million was recognized for the three months ended March 30, 2024. During the three months ended March 30, 2024, 168,000 shares of common stock were issued pursuant to the exercise of stock options at a weighted-average exercise price of $8.56 per share. As of March 30, 2024, unrecognized stock-based compensation expense of $87.8 million related to stock options, net of estimated forfeitures, is expected to be recognized over a weighted-average period of 2.3 years. Employee Stock Purchase Plans The Company maintains two employee stock purchase plans - the Amended and Restated Employee Stock Purchase Plan (the “ESPP”) and the Amended and Restated 2017 Nonqualified Employee Stock Purchase Plan (the “NQ ESPP”). The ESPP allows eligible employees to purchase shares of the Company’s common stock through payroll deductions of up to 15% of their eligible compensation subject to certain Internal Revenue Code limitations. The offering periods under the ESPP are two six-month offering periods from August 15 th through February 14 th and February 15 th through August 14 th of each year. The price of common stock purchased under the ESPP is 85% of the lower of the fair market value of the common stock on the commencement date and the end date of each six-month offering period. As of March 30, 2024, there were 4.3 million shares available for issuance under the ESPP. During the three months ended March 30, 2024, 0.2 million shares were purchased under the ESPP. As of March 30, 2024, unrecognized stock-based compensation expense of $0.9 million related to the ESPP is expected to be recognized over a remaining service period of 0.4 years. The NQ ESPP allows eligible employees to purchase shares of the Company’s common stock through payroll deductions of up to 25% of their eligible recurring compensation. Eligible employees have the right to (a) purchase the maximum number of whole shares of common stock that can be purchased with the elected payroll deductions during each offering period for which the employee is enrolled at a purchase price equal to the closing price of the Company’s common stock on the last day of such offering period and (b) receive an equal number of shares of the Company’s common stock that are subject to a risk of forfeiture in the event the employee terminates employment within the one year period immediately following the purchase date. The NQ ESPP provides quarterly offering periods from February 8 th through May 7 th , May 8 th through August 7 th , August 8 th through November 7 th and November 8 th through February 7 th of each year, with a maximum of 0.25 million shares allocated per purchase period. The maximum number of shares of common stock currently authorized for issuance under the NQ ESPP is 7.5 million shares. As of March 30, 2024, there were 3.1 million shares available for issuance under the NQ ESPP. During the three months ended March 30, 2024, 0.2 million shares were purchased and issued. As of March 30, 2024, unrecognized stock-based compensation expense of $11.3 million related to the NQ ESPP is expected to be recognized over a remaining weighted-average service period of 0.8 years. Stock-Based Compensation The following table summarizes stock-based compensation expense (in thousands): Three Months Ended March 30, April 1, Cost of revenue $ 636 $ 800 Sales and marketing 4,850 4,432 Research and development 4,515 4,312 General and administrative 6,855 6,676 $ 16,856 $ 16,220 Income tax benefit recognized $ 3,312 $ 4,153 Stock Repurchase Program

Revenue from Contracts with Cus

Revenue from Contracts with Customers	3 Months Ended
	Mar. 30, 2024
Revenue from Contract with Customer [Abstract]
Revenue from Contracts with Customers	Revenue from Contracts with Customers The Company develops, markets and sells a broadband platform and managed services, and there are no segment managers who are held accountable for operations, operating results and plans for levels or components below the Company unit level. Accordingly, the Company is considered to be a single reporting segment and operating unit structure. The Company’s chief operating decision maker is the Company’s Chief Executive Officer, who reviews financial information presented on a Company-wide basis, for purposes of allocating resources and evaluating financial performance. The following is a summary of revenue disaggregated by geographic region based upon the location of the customers (in thousands): Three Months Ended March 30, 2024 April 1, 2023 United States $ 210,089 $ 227,939 Americas ex U.S. 7,136 7,538 Europe 6,860 12,368 Middle East & Africa 1,889 1,773 Asia Pacific 336 390 $ 226,310 $ 250,008 Contract Asset Contract assets include amounts recognized as revenue prior to the Company’s contractual right to bill the customer. Amounts are billed in accordance with the agreed-upon contractual terms. Contract assets were $3.3 million as of March 30, 2024 as compared to $4.7 million as of December 31, 2023, and are included in prepaid expenses and other current assets on the Condensed Consolidated Balance Sheets. The Company expects to bill 46% of the March 30, 2024 balance during 2024. Contract Liability Deferred revenue was $63.9 million and $61.5 million as of March 30, 2024 and December 31, 2023, respectively. The increase in the deferred revenue balance for the three months ended March 30, 2024 was driven by cash payments received or due in advance of satisfying the Company’s performance obligations offset by $14.0 million of revenue recognized that was included in the deferred revenue balance at the beginning of the period. Revenue allocated to remaining performance obligations (“RPOs”) represents contract revenue that has not yet been recognized, which includes deferred revenue and amounts that will be invoiced and recognized as revenue in future periods but excludes variable consideration where the monthly invoicing is based on usage or where actual usage exceeds the minimum commitment. RPOs were $245.2 million as of March 30, 2024, and the Company expects to recognize as revenue 40% of this amount over the next 12 months and nearly all of the remainder over the two years thereafter. Contract Costs The Company capitalizes certain sales commissions related primarily to multi-year subscriptions and extended warranty support for which the expected amortization period is greater than one year. As of March 30, 2024 and December 31, 2023, the unamortized balance of deferred commissions was $11.8 million and $12.0 million, respectively. For the three months ended March 30, 2024 and April 1, 2023, the amount of amortization was $2.0 million and $1.3 million, respectively. There was no impairment loss in relation to the costs capitalized for these periods. Concentration of Customer Risk No customer accounted for more than 10% of the Company’s revenue for the three months ended March 30, 2024 and April 1, 2023.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 30, 2024
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The following table presents income taxes and the effective tax rates for the periods indicated (in thousands, except percentages): Three Months Ended March 30, April 1, Income before income taxes $ 468 $ 11,409 Income taxes $ 365 $ 1,811 Effective tax rate 78.0 % 15.9 % The Company has historically recorded its interim period provision for income taxes by applying a forecasted annual effective tax rate to year-to-date earnings and adjusting for discrete items. However, due to the level of forecasted provision for income taxes relative to the forecasted pre-tax income used in computing the effective tax rate, the effective tax rate is highly sensitive to fluctuations in pre-tax income and does not provide a reasonable estimate for income taxes in the interim period. As such, the Company has computed its provision for income taxes for the three months ended March 30, 2024 using an actual year-to-date tax calculation. The Company plans to revert to applying a forecasted annual effective tax rate to year-to-date earnings and adjusting for discrete items once that method produces more reasonable results. The Company’s effective tax rate for the three months ended March 30, 2024 and April 1, 2023 differed from the statutory federal corporate tax rate of 21% primarily due to state taxes and the effect of non-deductible stock-based compensation for executive officers offset by the favorable impact of U.S. federal research tax credits, excess tax benefits from stock-based compensation and the U.S. tax impact of foreign operations. The Company has net deferred tax assets that have arisen primarily as a result of temporary differences, net operating loss carryforwards, capitalized research and development costs and tax credits. The Company’s ability to realize a deferred tax asset is based on its ability to generate sufficient future taxable income within the applicable carryforward period and subject to any applicable limitations. Management believes that it is more likely than not that the Company will utilize a significant portion of its deferred tax assets. The Company maintained a valuation of $29.9 million the three months ended March 30, 2024 on certain U.S. federal and state deferred tax assets that the Company believes are not more likely than not to be realized in future periods. The Company considered scheduled reversals of deferred tax liabilities, historic profitability, projected future taxable income, ongoing tax planning strategies and other matters, including the period over which its deferred tax assets will be recoverable, in assessing the need for and the amount of the valuation allowance. In the event that actual results differ from these estimates, or if the Company decides to adjust these estimates in the future periods, further adjustments to its valuation allowance may be recorded, which could materially impact the Company’s financial position and net income in the period of the adjustment. In December 2021, the Organization for Economic Cooperation and Development enacted model rules for a new global minimum tax framework (“Pillar Two”), and certain governments in countries which the Company operates have enacted local Pillar Two legislation, with an effective date from January 1, 2024. The Company currently does not expect Pillar Two to have a material impact on its financial statements.

Net Income Per Common Share

Net Income Per Common Share	3 Months Ended
	Mar. 30, 2024
Earnings Per Share [Abstract]
Net Income Per Common Share	Net Income Per Common Share The following table sets forth the computation of basic and diluted net income per common share for the periods indicated (in thousands, except per share data): Three Months Ended March 30, April 1, Numerator: Net income $ 103 $ 9,598 Denominator: Weighted-average common shares outstanding used to compute basic net income per share 65,338 66,044 Effect of dilutive common stock equivalents 2,781 3,664 Weighted-average common shares outstanding used to compute diluted net income per share 68,119 69,708 Net income per common share: Basic net income per common share $ 0.00 $ 0.15 Diluted net income per common share $ 0.00 $ 0.14 Potentially dilutive shares excluded, weighted average 7,413 3,023 Potentially dilutive shares have been excluded from the computation of diluted net income per common share when their effect is antidilutive. These antidilutive shares were from stock options.

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended
	Mar. 30, 2024	Apr. 01, 2023
Pay vs Performance Disclosure
Net income	$ 103	$ 9,598

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Mar. 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

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 30, 2024
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed consolidated financial statements, including the accounts of Calix, Inc. and its wholly-owned subsidiaries, have been prepared in accordance with the requirements of the U.S. Securities and Exchange Commission (“SEC”) for interim reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by U.S. generally accepted accounting principles (“GAAP”) can be condensed or omitted. In the opinion of management, the financial statements include all normal and recurring adjustments that are considered necessary for the fair presentation of the Company’s financial position and operating results. All intercompany balances and transactions have been eliminated in consolidation. The Condensed Consolidated Balance Sheet as of December 31, 2023 has been derived from the audited financial statements at that date. The results of the Company’s operations can vary during each quarter of the year. Therefore, the results and trends in these interim financial statements may not be the same as those for the full year or any future periods. The information included in this Quarterly Report on Form 10-Q should be read in conjunction with the audited financial statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2023. The Company’s fiscal year begins on January 1 st and ends on December 31 st . Quarterly periods are based on a 4-4-5 calendar with the first quarter ending on the Saturday closest to March 31 st . As a result, the Company had one less day in the three months ended March 30, 2024 than for the three months ended April 1, 2023. The preparation of financial statements in conformity with GAAP for interim financial reporting requires management to make estimates and assumptions that affect the amounts reported in the condensed consolidated financial statements and accompanying notes. Actual results could differ from those estimates.
Newly Adopted Accounting Standard and Recent Accounting Pronouncements Not Yet Adopted	Newly Adopted Accounting Standard The Company did not adopt any new accounting standards during the three months ended March 30, 2024 that were significant to the Company. Recent Accounting Pronouncements Not Yet Adopted There have been no additional accounting pronouncements or changes in accounting pronouncements during the three months ended March 30, 2024 as compared to the recent accounting pronouncements described in the Company’s Annual Report on Form 10-K for the year ended December 31, 2023, that are significant or expected to be significant to the Company.
Cash and Cash Equivalents	The Company has invested its excess cash primarily in money market funds and highly liquid marketable securities such as U.S. treasury securities, corporate debt instruments, commercial paper and U.S. government securities. The Company considers all investments with maturities of three months or less when purchased to be cash equivalents. Marketable securities represent highly liquid U.S. treasury securities, corporate debt instruments, commercial paper and U.S. government securities with maturities greater than 90 days at date of purchase. Cash equivalents are stated at amounts that approximate fair value based on quoted market prices. Marketable securities are recorded at their fair values. Marketable securities with maturities greater than one year are classified as current because management considers all marketable securities to be available for current operations.
Fair Value Measurements	The Company measures its cash equivalents and marketable securities at fair value on a recurring basis. Fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. The Company utilizes the following three-tier value hierarchy, which prioritizes the inputs used in measuring fair value: Level 1 – Observable inputs that reflect quoted prices (unadjusted) for identical assets or liabilities in active markets. Level 2 – Observable inputs other than quoted prices included in Level 1 for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, and model-driven valuations in which all significant inputs and significant value drivers are observable in active markets. Level 3 – Unobservable inputs to the valuation derived from fair valuation techniques in which one or more significant inputs or significant value drivers are unobservable. The fair value hierarchy also requires the Company to maximize the use of observable inputs, when available, and to minimize the use of unobservable inputs when determining inputs and determining fair value.
Revenue Recognition	The Company develops, markets and sells a broadband platform and managed services, and there are no segment managers who are held accountable for operations, operating results and plans for levels or components below the Company unit level. Accordingly, the Company is considered to be a single reporting segment and operating unit structure. The Company’s chief operating decision maker is the Company’s Chief Executive Officer, who reviews financial information presented on a Company-wide basis, for purposes of allocating resources and evaluating financial performance.

Cash, Cash Equivalents and Ma_2

Cash, Cash Equivalents and Marketable Securities (Tables)	3 Months Ended
	Mar. 30, 2024
Cash and Cash Equivalents [Abstract]
Schedule of cash and cash equivalents	Cash, cash equivalents and marketable securities consisted of the following (in thousands): March 30, December 31, Cash and cash equivalents: Cash $ 34,063 $ 18,040 Commercial paper 28,704 32,837 Money market funds 21,556 2,563 U.S. government securities 3,098 9,969 U.S. government agency securities 997 — Total cash and cash equivalents 88,418 63,409 Marketable securities: U.S. government securities 83,412 92,277 U.S. government agency securities 40,287 43,521 Commercial paper 20,366 14,139 Corporate debt securities 6,999 7,000 Municipal securities — — Total marketable securities 151,064 156,937 $ 239,482 $ 220,346
Schedule of Debt securities, available-for-sale	The amortized cost and fair value of marketable securities were as follows (in thousands): As of March 30, 2024 Amortized Cost Unrealized Losses Fair Value U.S. government securities $ 86,588 $ (78) $ 86,510 Commercial paper 49,092 (22) 49,070 U.S. government agency securities 41,439 (155) 41,284 Corporate debt securities 7,027 (28) 6,999 $ 184,146 $ (283) $ 183,863 As of December 31, 2023 Amortized Cost Unrealized Losses Fair Value U.S. government securities $ 102,167 $ 80 $ 102,247 Commercial paper 47,003 (28) 46,975 U.S. government agency securities 43,573 (52) 43,521 Corporate debt securities 6,999 1 7,000 $ 199,742 $ 1 $ 199,743

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 30, 2024
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets Measured on Recurring Basis	The following tables sets forth the Company’s financial assets measured at fair value on a recurring basis based on the three-tier fair value hierarchy (in thousands): As of March 30, 2024 Level 1 Level 2 Total Money market funds $ 21,556 $ — $ 21,556 U.S. government securities 86,510 — 86,510 Commercial paper — 49,070 49,070 U.S. government agency securities — 41,284 41,284 Corporate debt securities — 6,999 6,999 $ 108,066 $ 97,353 $ 205,419 As of December 31, 2023 Level 1 Level 2 Total Money market funds $ 2,563 $ — $ 2,563 U.S. government securities 102,246 — 102,246 Commercial paper — 46,976 46,976 U.S. government agency securities — 43,521 43,521 Corporate debt securities — 7,000 7,000 $ 104,809 $ 97,497 $ 202,306

Balance Sheet Details (Tables)

Balance Sheet Details (Tables)	3 Months Ended
	Mar. 30, 2024
Balance Sheet Related Disclosures [Abstract]
Schedule of accounts receivable, net	Accounts receivable, net consisted of the following (in thousands): March 30, December 31, Accounts receivable $ 100,617 $ 126,331 Allowance for doubtful accounts (310) (304) $ 100,307 $ 126,027
Schedule of inventory	Inventory consisted of the following (in thousands): March 30, December 31, Raw materials $ 25,675 $ 22,119 Finished goods 94,107 110,866 $ 119,782 $ 132,985
Schedule of prepaid expenses and other current assets	Prepaid expenses and other current assets consisted of the following (in thousands): March 30, December 31, Supplier deposits $ 76,131 $ 78,131 Prepaid expenses and other current assets 43,083 40,467 $ 119,214 $ 118,598
Schedule of property and equipment, net	Property and equipment, net consisted of the following (in thousands): March 30, December 31, Test equipment $ 52,838 $ 50,853 Computer equipment 14,008 13,615 Software 10,534 12,972 Leasehold improvements 2,107 2,122 Furniture and fixtures 1,267 1,283 Total 80,754 80,845 Accumulated depreciation and amortization (51,878) (51,384) $ 28,876 $ 29,461
Schedule of accrued liabilities	Accrued liabilities consisted of the following (in thousands): March 30, December 31, Component inventory held by suppliers $ 25,536 $ 32,182 Compensation and related benefits 22,630 36,741 Professional and consulting fees 6,985 7,717 Current portion of warranty and retrofit 5,581 5,655 Operating leases 4,236 4,142 Taxes payable 4,165 4,317 Litigation settlement 3,250 3,250 Product returns 3,040 2,897 Customer advances or rebates 3,038 5,967 Insurance 2,106 2,107 Business events — 2,938 Other 7,038 8,314 $ 87,605 $ 116,227
Schedule of product warranty activities	Changes in the Company’s accrued warranty and retrofit liability were as follows (in thousands): Three Months Ended March 30, April 1, Balance at beginning of period $ 8,029 $ 8,386 Accruals for product warranty and retrofit 339 1,016 Cost of warranty and retrofit claims (713) (957) Balance at end of period $ 7,655 $ 8,445

Commitments and Contingencies (

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 30, 2024
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Rental Payments for Operating Leases	Future minimum payments under the non-cancelable operating leases consisted of the following as of March 30, 2024 (in thousands): Period Future Minimum Lease Payments Remainder of 2024 $ 3,522 2025 4,545 2026 1,672 2027 1,240 2028 and thereafter 1,048 Total future minimum lease payments 12,027 Less imputed interest (866) $ 11,161
Schedule of Lessee, Operating Lease Liability	As of March 30, 2024, the operating lease liability consisted of the following (in thousands): Accrued liabilities - current portion of operating leases $ 4,236 Operating leases 6,925 $ 11,161

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	3 Months Ended
	Mar. 30, 2024
Equity [Abstract]
Schedule of Disclosure of Share-Based Compensation Arrangements by Share-Based Payment Award	The following table summarizes stock-based compensation expense (in thousands): Three Months Ended March 30, April 1, Cost of revenue $ 636 $ 800 Sales and marketing 4,850 4,432 Research and development 4,515 4,312 General and administrative 6,855 6,676 $ 16,856 $ 16,220 Income tax benefit recognized $ 3,312 $ 4,153

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Tables)	3 Months Ended
	Mar. 30, 2024
Revenue from Contract with Customer [Abstract]
Schedule of Revenue From External Customers by Geographic Areas	The following is a summary of revenue disaggregated by geographic region based upon the location of the customers (in thousands): Three Months Ended March 30, 2024 April 1, 2023 United States $ 210,089 $ 227,939 Americas ex U.S. 7,136 7,538 Europe 6,860 12,368 Middle East & Africa 1,889 1,773 Asia Pacific 336 390 $ 226,310 $ 250,008

Income Taxes (Tables)

Income Taxes (Tables)	3 Months Ended
	Mar. 30, 2024
Income Tax Disclosure [Abstract]
Schedule of Income Taxes	The following table presents income taxes and the effective tax rates for the periods indicated (in thousands, except percentages): Three Months Ended March 30, April 1, Income before income taxes $ 468 $ 11,409 Income taxes $ 365 $ 1,811 Effective tax rate 78.0 % 15.9 %

Net Income Per Common Share (Ta

Net Income Per Common Share (Tables)	3 Months Ended
	Mar. 30, 2024
Earnings Per Share [Abstract]
Schedule of Net Income Per Share	The following table sets forth the computation of basic and diluted net income per common share for the periods indicated (in thousands, except per share data): Three Months Ended March 30, April 1, Numerator: Net income $ 103 $ 9,598 Denominator: Weighted-average common shares outstanding used to compute basic net income per share 65,338 66,044 Effect of dilutive common stock equivalents 2,781 3,664 Weighted-average common shares outstanding used to compute diluted net income per share 68,119 69,708 Net income per common share: Basic net income per common share $ 0.00 $ 0.15 Diluted net income per common share $ 0.00 $ 0.14 Potentially dilutive shares excluded, weighted average 7,413 3,023

Cash, Cash Equivalents and Ma_3

Cash, Cash Equivalents and Marketable Securities - Summary of Cash and Cash Equivalents (Details) - USD ($)	3 Months Ended
	Mar. 30, 2024	Apr. 01, 2023	Dec. 31, 2023
Cash and Cash Equivalents [Line Items]
Realized gains and losses on marketable securities	$ 0	$ 0
Total cash and cash equivalents	88,418,000		$ 63,409,000
Marketable securities	151,064,000		156,937,000
Total cash, cash equivalents, and marketable securities	239,482,000		220,346,000
U.S. government securities | Short-Term Marketable Securities
Cash and Cash Equivalents [Line Items]
Marketable securities	83,412,000		92,277,000
U.S. government agency securities
Cash and Cash Equivalents [Line Items]
Marketable securities	40,287,000		43,521,000
U.S. government agency securities | Short-Term Marketable Securities
Cash and Cash Equivalents [Line Items]
Marketable securities	41,284,000		43,521,000
Commercial paper
Cash and Cash Equivalents [Line Items]
Marketable securities	20,366,000		14,139,000
Corporate debt securities
Cash and Cash Equivalents [Line Items]
Marketable securities	6,999,000		7,000,000
Corporate debt securities | Short-Term Marketable Securities
Cash and Cash Equivalents [Line Items]
Marketable securities	6,999,000		7,000,000
Municipal securities
Cash and Cash Equivalents [Line Items]
Marketable securities	0		0
Cash
Cash and Cash Equivalents [Line Items]
Cash	34,063,000		18,040,000
Commercial paper
Cash and Cash Equivalents [Line Items]
Cash equivalents	28,704,000		32,837,000
Money market funds
Cash and Cash Equivalents [Line Items]
Cash equivalents	21,556,000		2,563,000
U.S. government securities
Cash and Cash Equivalents [Line Items]
Cash equivalents	3,098,000		9,969,000
U.S. government agency securities
Cash and Cash Equivalents [Line Items]
Cash equivalents	$ 997,000		$ 0

Cash, Cash Equivalents and Ma_4

Cash, Cash Equivalents and Marketable Securities - Schedule of Marketable Securities (Details) - USD ($) $ in Thousands	Mar. 30, 2024	Dec. 31, 2023
Debt Securities, Available-for-sale [Line Items]
Fair Value	$ 151,064	$ 156,937
Short-Term Marketable Securities And Cash Equivalents
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	184,146	199,742
Unrealized Losses	(283)	1
Fair Value	183,863	199,743
U.S. government securities | Short-Term Marketable Securities And Cash Equivalents
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	86,588	102,167
Unrealized Losses	(78)	80
Fair Value	86,510	102,247
U.S. government securities | Short-Term Marketable Securities
Debt Securities, Available-for-sale [Line Items]
Fair Value	83,412	92,277
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Fair Value	20,366	14,139
Commercial paper | Short-Term Marketable Securities And Cash Equivalents
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	49,092	47,003
Unrealized Losses	(22)	(28)
Fair Value	49,070	46,975
U.S. government agency securities
Debt Securities, Available-for-sale [Line Items]
Fair Value	40,287	43,521
U.S. government agency securities | Short-Term Marketable Securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	41,439	43,573
Unrealized Losses	(155)	(52)
Fair Value	41,284	43,521
Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Fair Value	6,999	7,000
Corporate debt securities | Short-Term Marketable Securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	7,027	6,999
Unrealized Losses	(28)	1
Fair Value	$ 6,999	$ 7,000

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	Mar. 30, 2024	Dec. 31, 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	$ 151,064	$ 156,937
Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	20,366	14,139
U.S. government agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	40,287	43,521
Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	6,999	7,000
Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	205,419	202,306
Fair Value, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	108,066	104,809
Fair Value, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	97,353	97,497
Fair Value, Recurring | U.S. government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	86,510	102,246
Fair Value, Recurring | U.S. government securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	86,510	102,246
Fair Value, Recurring | U.S. government securities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	0	0
Fair Value, Recurring | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	49,070	46,976
Fair Value, Recurring | Commercial paper | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	0	0
Fair Value, Recurring | Commercial paper | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	49,070	46,976
Fair Value, Recurring | U.S. government agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	41,284	43,521
Fair Value, Recurring | U.S. government agency securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	0	0
Fair Value, Recurring | U.S. government agency securities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	41,284	43,521
Fair Value, Recurring | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	6,999	7,000
Fair Value, Recurring | Corporate debt securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	0	0
Fair Value, Recurring | Corporate debt securities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	6,999	7,000
Fair Value, Recurring | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	21,556	2,563
Fair Value, Recurring | Money market funds | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	21,556	2,563
Fair Value, Recurring | Money market funds | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	$ 0	$ 0

Balance Sheet Details - Account

Balance Sheet Details - Accounts Receivable (Details) - USD ($) $ in Thousands	Mar. 30, 2024	Dec. 31, 2023
Summary of accounts receivable, net
Accounts receivable	$ 100,617	$ 126,331
Allowance for doubtful accounts	(310)	(304)
Accounts receivable, net	$ 100,307	$ 126,027

Balance Sheet Details - Invento

Balance Sheet Details - Inventory (Details) - USD ($) $ in Thousands	Mar. 30, 2024	Dec. 31, 2023
Summary of inventory, net
Raw materials	$ 25,675	$ 22,119
Finished goods	94,107	110,866
Total inventory	$ 119,782	$ 132,985

Balance Sheet Details - Prepaid

Balance Sheet Details - Prepaid Expenses and Other Assets (Details) - USD ($) $ in Thousands	Mar. 30, 2024	Dec. 31, 2023
Balance Sheet Related Disclosures [Abstract]
Supplier deposits	$ 76,131	$ 78,131
Prepaid expenses and other current assets	43,083	40,467
Total prepaid expense and other assets	$ 119,214	$ 118,598

Balance Sheet Details - Propert

Balance Sheet Details - Property and Equipment, net (Details) - USD ($) $ in Thousands	Mar. 30, 2024	Dec. 31, 2023
Summary of property and equipment, net
Property and equipment, gross	$ 80,754	$ 80,845
Accumulated depreciation and amortization	(51,878)	(51,384)
Property and equipment, net	28,876	29,461
Test equipment
Summary of property and equipment, net
Property and equipment, gross	52,838	50,853
Computer equipment
Summary of property and equipment, net
Property and equipment, gross	14,008	13,615
Software
Summary of property and equipment, net
Property and equipment, gross	10,534	12,972
Leasehold improvements
Summary of property and equipment, net
Property and equipment, gross	2,107	2,122
Furniture and fixtures
Summary of property and equipment, net
Property and equipment, gross	$ 1,267	$ 1,283

Balance Sheet Details - Accrued

Balance Sheet Details - Accrued Liabilities (Details) - USD ($) $ in Thousands	Mar. 30, 2024	Dec. 31, 2023
Summary of accrued liabilities
Component inventory held by suppliers	$ 25,536	$ 32,182
Compensation and related benefits	22,630	36,741
Professional and consulting fees	6,985	7,717
Current portion of warranty and retrofit	5,581	5,655
Operating leases	4,236	4,142
Taxes payable	4,165	4,317
Litigation settlement	3,250	3,250
Product returns	3,040	2,897
Customer advances or rebates	3,038	5,967
Insurance	2,106	2,107
Business events	0	2,938
Other	7,038	8,314
Total accrued liabilities	$ 87,605	$ 116,227

Balance Sheet Details - Warrant

Balance Sheet Details - Warranty Reserve (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 30, 2024	Apr. 01, 2023
Movement in Standard Product Warranty Accrual [Roll Forward]
Balance at beginning of period	$ 8,029	$ 8,386
Accruals for product warranty and retrofit	339	1,016
Cost of warranty and retrofit claims	(713)	(957)
Balance at end of period	$ 7,655	$ 8,445

Commitments and Contingencies -

Commitments and Contingencies - Operating Leases (Details) $ in Thousands	Mar. 30, 2024 USD ($)
Commitments and Contingencies Disclosure [Abstract]
Remainder of 2024	$ 3,522
2025	4,545
2026	1,672
2027	1,240
2028 and thereafter	1,048
Total future minimum lease payments	12,027
Less imputed interest	(866)
Operating lease liability	$ 11,161

Commitments and Contingencies_2

Commitments and Contingencies - Operating Lease Liability (Details) - USD ($) $ in Thousands	Mar. 30, 2024	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Accrued liabilities - current portion of operating leases	$ 4,236	$ 4,142
Operating leases	6,925	$ 7,421
Operating lease liability	$ 11,161
Operating lease, liability, current, statement of financial position	Accrued Liabilities, Current

Commitments and Contingencies_3

Commitments and Contingencies - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 30, 2024	Apr. 01, 2023	Dec. 31, 2023
Commitments and Contingencies [Line Items]
Total future minimum lease payments	$ 12,027
Weighted average operating discount rate used to determine the operating lease liability (percent)	5.10%
Weighted average remaining lease term for operating lease	3 years 1 month 6 days
Rent expense	$ 1,100	$ 1,200
Operating lease, payments	1,100	$ 1,200
Accrued customer rebates/prepayments	25,536		$ 32,182
Outstanding purchase commitments	146,800		$ 176,300
San Jose, California
Commitments and Contingencies [Line Items]
Total future minimum lease payments	$ 4,300

Stockholders' Equity - Stock Op

Stockholders' Equity - Stock Options (Details) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended
	Feb. 29, 2024 plan $ / shares shares	Mar. 30, 2024 USD ($) $ / shares shares	Apr. 01, 2023 USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted (in shares)		300,000
Weighted-average grant date fair value (in dollars per share) | $ / shares		$ 35.95
Stock-based compensation | $		$ 16,856	$ 16,220
Stock options exercised (in shares)		168,000
Weighted-average exercise price per share, stock options (in dollars per share) | $ / shares		$ 8.56
Unrecognized stock-based compensation expense, stock options | $		$ 87,800
Recognition period		2 years 3 months 18 days
2019 Equity Incentive Award Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future grant (in shares)		2,900,000
2021 Performance Targets | Stock Options | Period One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting rights, percentage		25%
2021 Performance Targets | Stock Options | Period Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period		3 years
2024 Performance Targets | Performance Based Stock Options | Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted (in shares)	2,400,000
Weighted-average grant date fair value (in dollars per share) | $ / shares	$ 34.26
Number of plans | plan	2
Award performance period	1 year
Stock-based compensation | $		$ 1,700
2024 Performance Targets | Performance Based Stock Options | Period One | Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting rights, percentage	25%
Grants in period percentage	75%
Award vesting period	1 year
Net income per share, target achievement performance threshold, percent	80%
Number of shares granted if non-GAAP income below 80% and bookings below 90% of target (in shares)	0
Performance target achievement, percentage of shares awarded	75%
Target achievement threshold for shares award sliding scale	120%
Shares award weighted percent	50%
Maximum combined payout percent	100%
2024 Performance Targets | Performance Based Stock Options | Period Two | Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting rights, percentage	75%
Grants in period percentage	25%
Award vesting period	36 months
Net income per share, target achievement performance threshold, percent	90%
Performance target achievement, percentage of shares awarded	75%
Target achievement threshold for shares award sliding scale	100%
Maximum combined payout percent	100%

Stockholders' Equity - Employee

Stockholders' Equity - Employee Stock Purchase Plans (Details) $ in Millions	3 Months Ended
	Mar. 30, 2024 USD ($) plan period shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of employee stock purchase plans | plan	2
Recognition period	2 years 3 months 18 days
Unrecognized stock-based compensation expense, stock options | $	$ 87.8
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
ESPP, maximum employee payroll deduction percentage	15%
Number of offering periods | period	2
Offering period	6 months
ESPP, discounted purchase price percentage	85%
Shares available for future grant (in shares)	4,300,000
Shares purchased under ESPP (in shares)	200,000
Unrecognized stock-based compensation expense | $	$ 0.9
Recognition period	4 months 24 days
Employee Stock Purchase Plan | 2017 Nonqualified Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
ESPP, maximum employee payroll deduction percentage	25%
Shares available for future grant (in shares)	3,100,000
Recognition period	9 months 18 days
Employee termination period following purchase date to receive shares subject to risk of forfeiture	1 year
Maximum number of shares allocated per purchase period	250,000
Number of shares authorized (in shares)	7,500,000
Number of shares issued (in shares)	200,000
Number of shares purchased (in shares)	200,000
Unrecognized stock-based compensation expense, stock options | $	$ 11.3

Stockholders' Equity - Stock-Ba

Stockholders' Equity - Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 30, 2024	Apr. 01, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$ 16,856	$ 16,220
Income tax benefit recognized	3,312	4,153
Cost of revenue
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	636	800
Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	4,850	4,432
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	4,515	4,312
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$ 6,855	$ 6,676

Stockholders' Equity - Stock Re

Stockholders' Equity - Stock Repurchase Program (Details) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions	3 Months Ended
	Mar. 30, 2024	Apr. 01, 2023
Equity [Abstract]
Shares repurchased (in shares)	0.1
Repurchases of common stock	$ 3,738	$ 1,183
Average price paid per share (in dollars per share)	$ 32.87
Remaining authorized repurchase amount	$ 109,900

Revenue from Contracts with C_3

Revenue from Contracts with Customers - Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 30, 2024	Apr. 01, 2023
Disaggregation of Revenue [Line Items]
Total revenues	$ 226,310	$ 250,008
United States
Disaggregation of Revenue [Line Items]
Total revenues	210,089	227,939
Americas ex U.S.
Disaggregation of Revenue [Line Items]
Total revenues	7,136	7,538
Europe
Disaggregation of Revenue [Line Items]
Total revenues	6,860	12,368
Middle East & Africa
Disaggregation of Revenue [Line Items]
Total revenues	1,889	1,773
Asia Pacific
Disaggregation of Revenue [Line Items]
Total revenues	$ 336	$ 390

Revenue from Contracts with C_4

Revenue from Contracts with Customers - Contract Asset and Liability (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 30, 2024	Dec. 31, 2023
Revenue from Contract with Customer [Abstract]
Contract with customer, asset	$ 3.3	$ 4.7
Contract with customer, asset, expected to be billed remainder of year, percent	46%
Deferred revenue	$ 63.9	$ 61.5
Contract with customer, liability, revenue recognized	$ 14

Revenue from Contracts with C_5

Revenue from Contracts with Customers - Performance Obligations (Details) $ in Millions	Mar. 30, 2024 USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation, amount	$ 245.2
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation, percentage	40%
Performance obligations expected to be satisfied, expected timing	12 months

Revenue from Contracts with C_6

Revenue from Contracts with Customers - Contract Costs (Details) - USD ($)	3 Months Ended
	Mar. 30, 2024	Apr. 01, 2023	Dec. 31, 2023
Revenue from Contract with Customer [Abstract]
Capitalized contract cost, gross	$ 11,800,000		$ 12,000,000
Capitalized contract cost, amortization	2,000,000	$ 1,300,000
Capitalized contract cost, impairment	$ 0	$ 0

Revenue from Contracts with C_7

Revenue from Contracts with Customers - Concentration Risk (Details) - Customer Concentration Risk - Accounts Receivable	3 Months Ended	12 Months Ended
	Mar. 30, 2024	Dec. 31, 2023
Customer One
Concentration Risk [Line Items]
Concentration risk, percentage	15%	19%
Customer Two
Concentration Risk [Line Items]
Concentration risk, percentage		14%

Income Taxes - Income Taxes And

Income Taxes - Income Taxes And The Effective Tax Rates (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 30, 2024	Apr. 01, 2023
Income Tax Disclosure [Abstract]
Income before income taxes	$ 468	$ 11,409
Income taxes	$ 365	$ 1,811
Effective tax rate	78%	15.90%

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) $ in Millions	Mar. 30, 2024 USD ($)
Income Tax Disclosure [Abstract]
Valuation allowance	$ 29.9

Net Income Per Common Share (De

Net Income Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 30, 2024	Apr. 01, 2023
Numerator:
Net income	$ 103	$ 9,598
Denominator:
Weighted-average common shares outstanding used to compute basic net income per share (in shares)	65,338	66,044
Effect of dilutive common stock equivalents (in shares)	2,781	3,664
Weighted-average common shares outstanding used to compute diluted net income per share (in shares)	68,119	69,708
Net income per common share:
Basic net income per common share (in dollars per share)	$ 0	$ 0.15
Diluted net income per common share (in dollars per share)	$ 0	$ 0.14
Potentially dilutive shares, weighted average (in shares)	7,413	3,023