Description of Business and Significant Accounting Policies | Description of Business and Summary of Significant Accounting Policies Description of Business A10 Networks, Inc. (together with our subsidiaries, the “Company”, “we”, “our” or “us”) was incorporated in California in 2004 and reincorporated in Delaware in March 2014. We are headquartered in San Jose, California and have wholly-owned subsidiaries throughout the world including Asia and Europe. We are a leading provider of secure application solutions and services that enable a new generation of intelligently connected companies with the ability to continuously improve cyber protection and digital responsiveness across dynamic Information Technology (“IT”) and network infrastructures. Our product portfolio seeks to address many of the cyber protection challenges and solution requirements. The portfolio consists of six secure application solutions; Thunder Application Delivery Controller (“ADC”), Lightning Application Delivery Controller (“Lightning ADC”), Thunder Carrier Grade Networking (“CGN”), Thunder Threat Protection System (“TPS”), Thunder SSL Insight (“SSLi”) and Thunder Convergent Firewall (“CFW”), and two intelligent management and automation tools; Harmony Controller and aGalaxy TPS. Our solutions are available in a variety of form factors, such as optimized hardware appliances, bare metal software, containerized software, virtual appliances and cloud-native software. Basis of Presentation The accompanying consolidated financial statements include those of A10 Networks, Inc. and its subsidiaries, and have been prepared in accordance with generally accepted accounting principles in the United States of America (“U.S. GAAP”) and pursuant to the rules and regulations of the United States Securities and Exchange Commission (the “SEC”). All intercompany accounts and transactions have been eliminated in consolidation. Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires us to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Those estimates and assumptions affect revenue recognition and deferred revenue, the allowance for credit losses for potential uncollectible amounts, the sales return reserve, the valuation of inventory, the fair value of marketable securities, contingencies and litigation, accrued liabilities, deferred commissions and the determination of fair value of stock-based compensation. These estimates are based on information available as of the date of the consolidated financial statements; therefore, actual results could differ from management’s estimates. Significant Accounting Policies Cash and Cash Equivalents Cash and cash equivalents include bank deposits and short-term, highly liquid investments purchased with an original maturity of 90 days or less. Our cash equivalents consist of money market funds. Marketable Securities We classify our investments in debt securities as available-for-sale and record these investments at fair value. We may sell these investments at any time before their maturity dates. Accordingly, we classify our securities, including those with maturities exceeding twelve months, as current assets and include them in marketable securities in the consolidated balance sheets. Unrealized gains and losses are reported in accumulated other comprehensive income (loss), net of taxes, in the consolidated statements of stockholders’ equity. Realized gains and losses are determined based on the specific identification method. Realized gains and losses and credit allowances and impairments due to credit losses, if any, on marketable securities are reported in interest and other income, net as incurred in the consolidated statements of operations. We regularly review our investment portfolio for impairment. If the estimated fair value of available-for-sale debt securities is less than its amortized cost basis, we determine if the difference, if any, is caused by expected credit losses and write-down the amortized cost basis of the securities if it is more likely than not we will be required or we intend to sell the securities before recovery of its amortized cost basis. Allowances for credit losses and write-downs are recognized in the non-operating income (expense) section of our consolidated statements of operations. The Company also invests in equity securities with readily determinable fair values which consist of investments in publicly traded companies. These investments are measured at fair value with changes in fair value recognized in our consolidated statements of operations. Fair Value Measurement Our financial instruments consist of cash, cash equivalents, marketable securities, accounts receivable and accounts payable. Our cash equivalents are measured and recorded at fair value on a recurring basis. Marketable securities are typically comprised of certificates of deposit, corporate securities, U.S. Treasury and agency securities, commercial paper, asset-backed securities and publicly trader equity securities and are measured at fair value on a recurring basis. The Company determines whether a credit loss exists for available-for-sale debt securities in an unrealized loss position. When the fair value of a security is below its amortized cost, the amortized cost will be reduced to its fair value and the resulting loss will be recorded in our consolidated statements of operations, if it is more likely than not that we are required to sell the impaired security before recovery of its amortized cost basis, or we have the intention to sell the security. If neither of these conditions are met, the Company considers the extent to which the fair value is less than the amortized cost, any changes to the rating of the security by a rating agency, and review of the issuer's financial statements. If factors indicate a credit loss exists, an allowance for credit loss is recorded through other expense, net, limited by the amount that the fair value is less than the amortized cost basis. For all available-for-sale debt securities, unrealized gains and the amount of unrealized loss relating to factors other than credit loss are reported as a separate component of accumulated other comprehensive loss in our consolidated balance sheets. Realized gains and losses are determined based on the specific identification method and are reported in our consolidated statements of operations. Financial instruments recorded at fair value are measured and classified using the three-level valuation hierarchy as described below: Level 1 — observable inputs for identical assets or liabilities, such as quoted prices in active markets. Level 2 — inputs other than the quoted prices in active markets that are observable either directly or indirectly. Level 3 — unobservable inputs in which there is little or no market data, which requires us to develop our own assumptions when pricing the financial instruments. Accounts receivable and accounts payable are stated at their carrying value, which approximates fair value due to the short time to the expected receipt or payment. Accounts Receivable and Allowance for Credit Losses Accounts receivable are unsecured and are recorded at invoice amounts, net of allowances for credit losses for any potential uncollectible amounts. We evaluate the collectability of our accounts receivable based on known collection risks and historical experience. We mitigate credit risk in respect to accounts receivable by performing periodic credit evaluations based on a number of factors, including past transaction experience, evaluation of credit history and review of the invoicing terms of the contract. We generally do not require our customers to provide collateral to support accounts receivable. In circumstances where we are aware of a specific customer’s inability to meet its financial obligations to us (for examples, bankruptcy filings or substantial downgrading of credit ratings), we record a specific allowance for credit losses against amounts due to reduce the net recognized receivable to the amount we reasonably believe will be collected. For all other customers, we record allowances for credit losses based on the length of time the receivables are past due and our historical experience of collections and write-offs. Inventory Inventory is stated at the lower of cost or net realizable value. Inventory cost is determined using first-in, first-out method. We regularly evaluate inventory for excess and obsolete products. Most of our inventory provisions relate to excess quantities of certain products, based on our inventory levels and future product purchase commitments compared to assumptions based on management’s assessment of future demand and market conditions. Inventory write-downs, once established, are not reversed as they establish a new cost basis for the inventory. Inventory write downs are included as a component of cost of products revenue in the consolidated statements of operations. Property and Equipment, Net Property and equipment are stated at cost, less accumulated depreciation and amortization. Depreciation and amortization is computed using the straight-line method over the estimated useful lives of the related assets. Depreciation and amortization on property and equipment, excluding leasehold improvements, ranges from one Leasehold improvements are amortized on a straight-line basis over the shorter of the estimated useful lives of the assets or the remaining lease term. Remaining amortization terms on leasehold improvements as of December 31, 2023 ranged from approximately one Leases The Company determines if an arrangement is a lease at inception. For leases where the Company is the lessee, right-of-use (“ROU”) assets represent the Company’s right to use the underlying asset for the term of the lease and are included within other non-current assets in the consolidated balance sheets, and the lease liabilities represent an obligation to make lease payments arising from the lease and are recorded within accrued liabilities and other non-current liabilities in the consolidated balance sheets. Lease liabilities are recognized at the lease commencement date based on the present value of the future lease payments over the lease term. The Company uses its incremental borrowing rate based on the information available at the commencement date of the underlying lease arrangement to determine the present value of lease payments. The ROU asset is determined based on the lease liability initially established and reduced for any prepaid lease payments and any lease incentives received. The lease term to calculate the ROU asset and related lease liability includes options to extend or terminate the lease when it is reasonably certain that the Company will exercise the option. The Company’s lease agreements generally do not contain any material variable lease payments, residual value guarantees or restrictive covenants. The Company elected the package of practical expedients permitted under the transition guidance, which allowed for the carry-forward of the Company’s historical lease classification and assessment on whether a contract is or contains a lease. The Company elected to not apply the new standard’s recognition requirements to leases with an initial term of 12 months or less and instead elected to recognize lease payments in the consolidated statements of operations on a straight-line basis over the lease term. Lease expense for operating leases is recognized on a straight-line basis over the lease term as an operating expense while expense for financing leases is recognized as depreciation expense and interest expense using the accelerated interest method of recognition. The Company accounts for lease components and non-lease components as a single lease component. Goodwill Goodwill represents the excess of purchase consideration over the fair values of assets acquired and liabilities assumed in a business combination. Goodwill is not amortized but is reviewed for possible impairment annually in the fourth quarter or more frequently if impairment indicators arise. We have identified a single reporting unit for the purpose of our goodwill impairment tests, and the fair value of our reporting unit has been determined by our enterprise value. We may elect to utilize a qualitative assessment to determine whether it is more likely than not that the fair value of our reporting unit is less than its carrying value. If, after assessing the qualitative factors, we determine that it is more likely than not that the fair value of our reporting unit is less than its carrying value, an impairment analysis will be performed. We compare the fair value of our reporting unit with its carrying amount and if the carrying value of the reporting unit exceeds its fair value, an impairment loss will be recognized for the amount by which the carrying amount of a reporting unit exceeds its fair value up to the amount of goodwill. We did not identify impairment of goodwill for any periods presented. Intangible Assets Intangible assets are recorded at fair value and amortized on a straight-line basis over their estimated useful lives, which ranged from 5 to 11 years. We evaluate our intangible assets for impairment at least annually and when indicators of impairment may exist. There were no impairment charges to our intangible assets during the years ended December 31, 2023, 2022 and 2021. Our purchased intangible assets were fully amortized as of December 31, 2021. Impairment of Long-Lived Assets We evaluate our property and equipment for impairment whenever events or changes in circumstances indicate that the carrying amount of our long-lived assets may not be recoverable. Recoverability of an asset group is measured by comparison of its carrying amount to the expected future undiscounted cash flows that the asset group is expected to generate. If it is determined that an asset group is not recoverable, an impairment loss is recorded in the amount by which the carrying amount of the asset group exceeds its fair value. Revenue Recognition We recognize revenue, net of applicable taxes, when we transfer control of promised goods or services to our customers in an amount that reflects the consideration to which we expect to be entitled to in exchange for those goods or services. We derive revenue from two sources: (i) products revenue, which includes hardware, perpetual software license and subscription offerings, which include term-based license agreements and software-as-a-service; and (ii) services revenue, which includes post contract support (“PCS”), professional services, and training. Revenue for term-based license agreements is recognized at a point in time when the Company delivers the software license to the customer and over time once the subscription term has commenced. For our software-as-a-service offerings, our customers do not take possession of the Company’s software but rather we provide access to the service via a hosting arrangement. Revenue in these arrangements is recognized over time as the services are provided. A substantial portion of our revenue is from sales of our products and services through distribution channel partners, such as resellers and distributors. We apply the following five-step revenue recognition model: • Identification of the contract, or contracts, with a customer • Identification of the performance obligations in the contract • Determination of the transaction price • Allocation of the transaction price to the performance obligations in the contract • Recognition of revenue when, or as, performance obligations are satisfied. Our customers predominantly purchase PCS services in conjunction with purchases of our products. PCS revenue includes arrangements for software support and technical support for our products. PCS is offered under renewable, fee-based contracts, which include technical support, hardware repair and replacement parts, bug fixes, patches, and unspecified upgrades on a when-and-if available basis. We recognize services revenue ratably over the term of the PCS contract, which is typically one year, but can be up to seven years. Billed but unearned PCS revenue is included in deferred revenue. Professional service revenue primarily consists of the fees we earn related to installation and consulting services. We recognize revenue from professional services upon delivery or completion of performance. Professional service arrangements are typically short term in nature and are largely completed within 30 to 90 days from the start of service. Revenue is recognized for training when the training course is delivered. Contracts with Multiple Performance Obligations Most of our contracts with customers, other than renewals of PCS, contain multiple performance obligations with a combination of products and PCS. Products and PCS generally qualify as distinct performance obligations. Our hardware includes embedded ACOS software, which together deliver the essential functionality of our products. For contracts which contain multiple performance obligations, we allocate revenue to each distinct performance obligation based on the standalone selling price (“SSP”). Judgment is required to determine the SSP for each distinct performance obligation. We use a range of amounts to estimate SSP for products and PCS sold together in a contract to determine whether there is a discount to be allocated based on the relative SSP of the various products and PCS. If we do not have an observable SSP, such as when we do not sell a product or service separately, then SSP is estimated using judgment and considering all reasonably available information such as market conditions and information about the size and/or purchase volume of the customer. We generally use a range of amounts to estimate SSP for individual products and services based on multiple factors including, but not limited to the sales channel (reseller, distributor or end-customer), the geographies in which our products and services are sold, and the size of the end-customer. We account for multiple contracts with a single partner as one arrangement if the contractual terms and/or substance of those agreements indicate that they may be so closely related that they are, in effect, parts of a single contract. We may occasionally accept returns to address customer satisfaction issues even though there is generally no contractual provision for such returns. We estimate returns for sales to customers based on historical return rates applied against current-period shipments. Specific customer returns and allowances are considered when determining our sales return reserve estimate. Consequently, we have chosen to apply the portfolio approach when possible, which we do not believe will happen frequently. Additionally, we will evaluate a portfolio of data, when possible, in various situations, rights of return and transactions with variable consideration. We report revenue net of sales taxes. We include shipping charges billed to customers in revenue and the related shipping costs are included in cost of product revenue. Deferred Contract Acquisition Costs We capitalize certain contract acquisition costs consisting of incremental sales commissions incurred to obtain customer contracts. Deferred commissions related to product revenues are recognized upon transfer of control to customers. Deferred commissions related to services revenue are recognized as the related performance obligations are met. Deferred commissions that will be recognized during the succeeding 12-month period are recorded as prepaid expenses and other current assets in the Company’s consolidated balance sheets, and the remaining portion is recorded as other non-current assets. Amortization of deferred commissions is included in sales and marketing expense in the consolidated statements of operations. Research and Development Costs Research and development efforts are focused on new product development and on developing additional functionality for our existing products. These expenses consist of personnel costs, and to a lesser extent, prototype materials, depreciation and certain allocated facilities and information technology costs. We expense research and development costs as incurred. Capitalization of Internal Use Software The company capitalizes costs incurred during the application development stage associated with the development of internal-use software systems. We account for the capitalization of internal-use software under ASC Topic 350-40, Internal-Use Software . Capitalized costs are included in property and equipment, net on the Company’s consolidated balance sheet. Once a project is available for general release to customers, the accumulated capitalized costs associated with that project will begin to be amortized over the estimated useful life of the software. Capitalization of Internally Developed Software to be Marketed and Sold In the first quarter of 2020, we began capitalizing software engineering labor costs related to certain long-term projects that are expected to take more than a year to complete. We account for the capitalization of labor costs under Accounting Standards Codification (“ASC”) Topic 985-20, Software to be Sold, Leased or Marketed . Once a long-term project is available for general release to customers, the accumulated capitalized labor costs associated with that project will begin to be amortized over the expected revenue-generating life of that project and are recorded in cost of sales. In December 2022, we released the software portion of our first capitalized project and impaired the uncompleted hardware portion that we determined would not generate sufficient revenue to justify the cost of completing it. When internal-use software that was previously capitalized is abandoned, the cost less the accumulated amortization, if any, is recorded as an operating expense. In September 2023, we released our second capitalized project after we impaired a portion of it after we determined the full carrying value was not recoverable. Stock-Based Compensation Stock-based compensation expense is measured on the grant date based on the fair value of the award and recognized on a straight-line basis over the requisite service period, reduced for actual forfeitures. The fair values of restricted stock units (“RSUs”) are estimated using our stock price at the close of the market on the grant date. The fair value of employee stock purchase rights is estimated using the Black-Scholes model on the grant date. The Black-Scholes model determines the fair value of share-based payment awards based on assumptions including expected term, stock price volatility and risk-free interest rate. Stock-based compensation expense related to shares not purchased due to terminations, or forfeitures, is reversed on the date of forfeiture. The fair values of market performance-based restricted stock units (“PSUs”) are estimated using the Monte Carlo simulation model, which uses the stock price, expected volatility and risk-free interest rate to determine the fair value. Warranty Costs Our appliance hardware and software generally carry a warranty period of 90 days. Estimates of future warranty costs are based on historical returns and the application of the historical return rates to our in-warranty installed base. Warranty costs to repair or replace items sold to customers have been insignificant for the years ended December 31, 2023, 2022 and 2021. Foreign Currency The functional currency of our foreign subsidiaries is the U.S. Dollar. Transactions denominated in non-functional currencies are remeasured to the functional currency at the average exchange rate for the period. Non-functional currency monetary assets and liabilities are remeasured to the functional currency using the exchange rate in effect at the balance sheet date, and non-monetary assets and liabilities are remeasured at historical exchange rates. Gains and losses related to remeasurement are recorded in interest and other income, net in the consolidated statements of operations. Income Taxes We account for income taxes using the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been recognized in our consolidated financial statements or in our tax returns. Estimates and judgments occur in the calculation of certain tax liabilities and in the determination of the recoverability of certain deferred income tax assets, which arise from temporary differences and carryforwards. Deferred income tax assets and liabilities are measured using the currently enacted tax rates that apply to taxable income in effect for the years in which those tax assets are expected to be realized or settled. We regularly assess the likelihood that our deferred tax assets will be recovered from future taxable income and, to the extent we believe, based upon the weight of available evidence, that it is more likely than not that all or a portion of deferred tax assets will not be realized, a valuation allowance is established through an adjustment to income tax expense. The factors used to assess the likelihood of realization of our deferred tax assets include our historical operating performance, our forecast of future taxable income and available tax planning strategies that could be implemented to realize the net deferred tax assets. Assumptions represent our best estimates and involve inherent uncertainties and the application of our judgment. We account for uncertainty in income taxes recognized in our consolidated financial statements by regularly reviewing our tax positions and benefits to be realized. We recognize tax liabilities based upon our estimate of whether, and the extent to which, additional taxes will be due when such estimates are more-likely-than-not to be sustained. An uncertain income tax position will not be recognized if it has less than a 50% likelihood of being sustained upon examination by taxing authorities. The provision for (benefit from) income taxes excludes the effects of any resulting tax reserves, or unrecognized tax benefits, that are considered appropriate as well as the related net interest and penalties. Advertising Costs Advertising costs are expensed when incurred. Advertising costs were $0.1 million, $0.2 million and $0.3 million for the years ended December 31, 2023, 2022 and 2021, respectively. Segment Information An operating segment is a component of an enterprise for which its discrete financial information is available and its operating results are regularly reviewed by our chief operating decision maker for resource allocation decisions and performance assessment. Our chief operating decision maker is our Chief Executive Officer. Our Chief Executive Officer reviews financial information presented on a consolidated basis for purposes of allocating resources and assessing performance of the Company. Accordingly, we have one reportable segment and one operating segment. Vendor Business Concentration We rely on third parties to manufacture our hardware appliances and we purchase raw materials from third-party vendors. We outsource substantially all of our manufacturing services to three independent manufacturers. In addition, we purchase certain strategic component inventory which is consigned to our third-party manufacturers. Other hardware components included in our products are sourced from various suppliers by our manufacturers and are principally industry standard parts and components that are available from multiple vendors. Concentration of Credit Risk and Significant Customers Financial instruments that potentially subject us to concentrations of credit risk consist of cash, cash equivalents, marketable securities and accounts receivable. Our cash, cash equivalents and marketable securities are held and invested in high-credit quality financial instruments by recognized financial institutions and are subject to minimum credit risk. Our accounts receivable are unsecured and represent amounts due to us based on contractual obligations of our customers. We mitigate credit risk in respect to accounts receivable by performing periodic credit evaluations based on a number of factors, including past transaction experience, evaluation of credit history and review of the invoicing terms of the contract. We generally do not require our customers to provide collateral to support accounts receivable. Significant customers, including distribution channel partners and direct customers (“end-customers”), are those which represent 10% or more of our total revenue for each period presented or our gross accounts receivable balance as of each respective balance sheet date. Revenues from our significant end-customers as a percentage of our total revenue are as follows: Years Ended December 31, 2023 2022 2021 Customer A 14% 11% 11% Customer B * 13% * * represents less than 10% of total revenue As of December 31, 2023, one customer accounted for 19% of our total gross accounts receivable. As of December 31, 2022, two customers accounted for 21% and 21% of our total gross accounts receivable. Recent Accounting Standards Not Yet Adopted In November 2023, the Financial Accounting Standards Board, or the FASB, issued Accounting Standards Update, or ASU, 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures , which requires public entities to disclose information about their reportable segments’ significant expenses and other segment items on an interim and annual basis. Public entities with a single reportable segment are required to apply the disclosure requirements in ASU 2023-07 , as well as all existing segment disclosures and reconciliation requirements in ASC 280, on an interim and annual basis. ASU 2023-07 is effective for fiscal years beginning after December 15, 2023, and for interim periods within fiscal years beginning after December 15, 2024, with early adoption permitted. We are currently evaluating the impact of adopting ASU 2023-07 . In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures , which requires public entities, on an annual basis, to provide disclosure of specific categories in the rate reconciliation, as well as disclosure of income taxes paid disaggregated by jurisdiction. ASU 2023-09 is effective for fiscal years beginning after December 15, 2024, with early adoption permitted. We are currently evaluating the impact of adopting ASU 2023-09 . There have been no other recent accounting pronouncements, changes in accounting pronouncements or recently adopted accounting guidance during the year ended December 31, 2023 that are of significance or potential significance to us. |