Senior Software Engineer

About this role

THE ROLE We're hiring a senior backend engineer to help build and scale the platform. You'll own big pieces of our GraphQL API, our serverless services, and the data model underneath. These are the systems that validate payments, onboard vendors, and keep tax and identity data safe. The team is small and senior. You'll design systems end to end, make real architectural decisions, and work directly with our fintech partners. Since our code moves money, getting the details right is most of the job. WHAT YOU'LL DO - Build and scale backend services in TypeScript on AWS Lambda, backed by PostgreSQL and Hasura GraphQL. - Own the data model and API surface: schema design, migrations, Hasura metadata, permissions, and GraphQL codegen. - Build and maintain integrations with our fintech and compliance partners. - Work with sensitive data (tax IDs, identity documents, payment details) behind encryption and strict access controls. - Implement the logic behind global payouts, W-9/W-8 collection, real-time tax validation, and 1099 generation. - Keep services observable in production with services like Honeycomb and Sentry - Write tests that earn their keep (Jest for unit and integration, Playwright for end-to-end) and help keep code review standards high. - Ship features alongside product and frontend engineers in a Next.js app, and mentor other engineers as the team grows. WHAT WE'RE LOOKING FOR - 5+ years building and running backend systems in production, including services you owned end to end. - Strong TypeScript and Node.js, and comfort designing relational data models in PostgreSQL. - Real experience with GraphQL APIs (Hasura or similar) and good instincts for schema design. - Hands-on AWS experience: Lambda, serverless architectures, and infrastructure as code (we use CloudFormation and the Serverless Framework). - You take security seriously. Authentication and authorization (we use Auth0 and JWTs), encryption, and careful PII handling should all be familiar ground. - You've integrated third-party APIs and thought hard about retries, idempotency, and what happens when things fail mid-payment. - Good habits around testing, observability, and CI/CD. - You write clearly and can make sensible tradeoffs without much supervision. NICE TO HAVE - You've built or maintained APIs at scale. - A background in fintech, payments, or compliance (KYC, tax, banking, or money movement). - Familiarity with other parts of our stack: Hasura, Segment, Twilio, SendGrid. - Experience building for users across many countries: multi-currency, internationalization, cross-border payments. SOME OF THE TOOLS WE USE TypeScript · Node.js 20 · Next.js · React · Hasura GraphQL · PostgreSQL · AWS Lambda · Serverless Framework · CloudFormation · AWS KMS · Auth0 · Apollo/GraphQL Codegen · Plaid · Unit · Codat · Persona · TaxBit · OpenTelemetry · Sentry · Pino · Jest · Playwright · Doppler · Docker PAY & BENEFITS - Salary range: $150,000–$180,000, depending on experience and location - Equity - Unlimited PTO - Medical, dental, and vision insurance - 401(k) plan WHY LUMANU The code you ship here moves real money for real people, usually within your first few weeks. The team is small enough that you'll have a real say in architecture, product, and process. And the problems are hard in a good way: payments, compliance, encryption, and infrastructure that spans 180 countries. Lumanu is an equal opportunity employer. We welcome applicants of all backgrounds and are committed to building an inclusive team.