Senior / Staff Software Engineer, Payments

Location: Florida (Miami preferred). Hybrid. About the Role Remitian is looking for a high-agency Staff Software Engineer to join our Payments team and own the systems that move money on our platform. The Payments team owns everything from a tax obligation becoming a payment through to the ledger that records every transaction: banking integrations and fee charges, automated payment integrations with tax authority portals, support for new payment types and tax authorities as the platform expands, and the subscription system for taxpayers and firms. Its mission is to make tax payments reliable, traceable, and effortless, no matter the payment type or tax authority behind it. This is a staff-level role, which means your scope spans the payments platform rather than a single feature area. You will work closely with the Payments team lead and the rest of the team on the design of our money-movement systems, contribute to the standards and patterns we build on, and help deliver work that reaches across team boundaries. You will write a lot of code, and you will add leverage through the design decisions you shape and the engineers you help grow along the way. You will work across the stack, from data models and services through to the surfaces our customers and internal teams use. We are looking for someone who has built money-movement systems before and knows the difference between a payment flow that works on the happy path and one that stays correct, traceable, and recoverable when the real world intervenes. This role is based in Florida, with Miami preferred, on a hybrid schedule of 3 to 4 days per week in office. Key Responsibilities Payments Domain Ownership Own money-movement workflows end to end, from a tax obligation becoming a payment through settlement and its record in the ledger. Own the banking integrations, fee charges, and transaction ledger that keep every movement of money accounted for. Design and evolve our automated payment integrations with tax authority portals, and make them reliable, observable, and recoverable. Drive support for new payment types and new tax authorities, turning each addition into repeatable patterns rather than one-off builds. Treat idempotency, reconciliation, and exact accounting as first-class design constraints rather than afterthoughts. Technical Leadership and Architecture Lead the design of significant payments systems and see the architectural decisions behind them through to production. Help shape technical direction for the Payments team alongside the team lead, and align it with the broader engineering roadmap (Staff role) Make and defend trade-offs around performance, scalability, security, correctness, and maintainability, and write those decisions down. Contribute to the engineering standards, patterns, and best practices the team builds on, and hold the bar in code and design review. Build alignment across teams on contracts and shared services, including the hard conversations that come with it. Full-Stack Product Development Design, build, and ship complex features across the stack, from data models and services through to UI. Translate ambiguous requirements into clean, maintainable, well-tested systems. Own the shared services other engineering teams depend on, and treat those teams as customers. Partner with product, design, and engineering leadership to scope and deliver substantial bodies of work. Reliability, Security, and Production Operations Own payments services in production, including their reliability, performance, and operational behaviour. Lead incident investigation and resolution, and drive the follow-up that prevents recurrence. Set the standard for observability, alerting, and testing on critical money-movement workflows, where a silent failure is worse than a loud one. Bring a security-first mindset to money movement, banking credentials, and sensitive taxpayer data in every review and design decision. Ownership, Mentorship, and Continuous Improvement Take real ownership of major areas of the payments platform and be accountable for their outcomes. Identify problems, propose solutions, and drive them to completion without waiting for direction. Mentor and grow other engineers through code review, pairing, and design feedback. Contribute to engineering culture, hiring, onboarding, and standards as the team grows. Push back, raise concerns, and surface ideas that improve the platform or how the team works. Who You Are 5+ years (Senior role) or 8+ years (Staff role) of experience as a software engineer, with a track record of designing and operating production systems at scale. Proven experience building and operating payments or money-movement systems, such as ledgers, banking integrations, or payment rails, where correctness and reconciliation were part of your responsibility. Deep, hands-on proficiency building production applications with C# and .NET, plus modern JavaScript or TypeScript. Strong experience using LLMs and AI tooling