Software Engineer, Financial Data & Payments

About Gusto At Gusto, we're on a mission to grow the small business economy. We handle the hard stuff — payroll, health insurance, 401(k)s, and HR — so owners can focus on their craft and their customers. With teams in Denver, San Francisco, and New York, we support more than 500,000 small businesses nationwide and are building a workplace that reflects the people we serve. All full-time employees receive competitive base pay, benefits, and equity (RSUs) — because everyone who helps build Gusto should share in its success. Offer amounts are determined by role, level, and location. Learn more about our Total Rewards philosophy. AI is a fundamental part of how work gets done at Gusto. We expect all team members to actively engage with AI tools relevant to their role and grow their fluency as the technology evolves. AI experience requirements vary by role and will be assessed during the interview process. About the Role: We’re hiring seasoned engineers to join our teams that work on the financial backbone of Gusto's money movement — the ledger, reconciliation, and reporting systems that account for every dollar, and the payment profile that determines how employers fund payroll and how employees and contractors get paid. As a Gusto Software Engineer at this level, you’ll be guiding projects end-to-end by driving large technical architectural decisions (focusing on scale and modularity), understanding how to take existing systems closer to desired end states, executing on projects, and maintaining code that powers core experiences. If you’re interested in building elegant software with far-reaching effects in our modern economy, join us! About the Team: Financial Data & Payment Profile (FDPP) sits inside Gusto's Payments organization, which moves money safely between partners, employers, employees, government authorities, and Gusto. FDPP owns the two things that every one of those movements depends on. Financial Data is the system of record for the money itself: the ledger and subledger behind every payment, the reconciliation that proves our books agree with our banks and partners, the investigation of the variances that surface when they do not, and the financial reporting that Accounting, Finance, and Compliance depend on. When Gusto needs to answer where a dollar is — and prove it — the answer comes from systems this team builds. Payment Profile is what makes a payment possible in the first place: the payment methods available to a customer, the bank accounts and connections behind them, the verification that makes those accounts trustworthy, and the profile state that decides whether a payment can happen at all. Hundreds of thousands of businesses depend on this being right the first time — and on it recovering gracefully when a bank account, a connection, or a preference changes. Here’s what you’ll do day-to-day: • Design, build, and test the financial data systems that record every dollar Gusto moves — the ledger and subledger that serve as the system of record, the transaction models underneath them, and the financial reporting that Accounting, Finance, Compliance, and our partners rely on to close the books • Build reconciliation at Gusto's scale: prove that our internal records agree with bank, processor, and partner statements, and make the breaks that fall out of that comparison traceable rather than mysterious • Lead variance investigation end-to-end — the tooling, instrumentation, and runbooks that turn "the numbers don't tie" into a specific root cause, and then into a fix that eliminates the whole class of break • Own the payment profile: how employers are set up to fund payroll and how employees and contractors are set up to be paid — the payment methods available and the rules that govern which apply to whom, the bank accounts and connections behind them, and the verification state that determines whether money can move at all • Make setup and verification something a small business can finish on its own — instant bank verification, graceful handling of broken or revoked connections, and a clear path back to a payable state when something changes • Help scale one of the largest Ruby/Rails and TypeScript/React applications in the world • Collaborate on complex and ambiguous problems with partnerships from Engineering, Product Management, Design, Data Science, Accounting, Finance, Compliance, Operations, and other cross-functional teams • Mentor and grow fellow engineers working to create holistic and scalable solutions Here’s what we're looking for: • Successful applicants have at least 10+ years of experience and the enthusiasm for a collaborative, test-driven environment • Experience building fault-tolerant, mission-critical software as well as designing and developing robust, distributed systems using multiple general-purpose programming languages • Experience influencing and guiding the work of multiple teams on scaling, refactoring, and optimizing legacy products • Experience architecting, building, and testing large-scale production level code that is maintainable, structured, and well-documented • An aptitude and interest in bringing clarity and simplicity to complex and ambiguous problems • Ability to communicate technical complexity and help facilitate informed tradeoffs • Experience in one or more of these domains is strongly preferred: ledger or subledger design, financial reconciliation, accounting systems, or payments infrastructure • Comfort with double-entry accounting concepts — journal entries, chart of accounts, debits and credits, and tying a subledger out to the general ledger — and the ability to work with accountants and controllers in their own vocabulary • Experience building systems where correctness, auditability, and immutability matter more than raw throughput, and where a silent data error is worse than an outage • Bonus: Experience with bank account verification, payment rails (ACH, wire, RTP), or third-party bankin