Backend Engineer – API Development

Backend Engineer – API Development. The role in one line: An independent backend engineer to help build, harden, and scale our secure APIs – strong on API craft, security, and testing, and able to help drive delivery, not just execute tickets.

Context: Work across our API surface, held to real financial-institution standards for security, reliability, and testing. It’s a deliberately simple, well-structured codebase. No internal/domain business knowledge required, that’s owned in-house. We need backend and API strength. Where they add the most value: Since internal logic is covered, their leverage is on the partner-facing platform and developer experience: Growing the API surface cleanly (new endpoints, webhooks/callbacks, richer querying), Developer experience – clear contracts, published API specs, integration docs, sandbox environments, Hardening – rate limiting, secret rotation, contract testing, pen-test remediation, Scaling – repeatable multi-partner onboarding, tenant isolation, load/performance testing, caching, Platform quality – SLOs, alerting, resilience patterns.

Ways of working: Independent and self-directing – takes a capability from spec → design → tested delivery without hand-holding, Helps manage the work – can break down a body of work, sequence it, and drive it to a clear “done”, Spec- and documentation-driven – at home working from and writing specs, acceptance criteria, and decision records; a clear, concise writer, Comfortable with AI-assisted / agentic development – this project is built heavily with agentic tooling; someone who can direct and review that output well is a real multiplier, Quality-first and pragmatic – treats security, testing, and observability as ship-blocking, while favoring simple solutions over over-engineering.

Requirements: Core skills: Modern backend development in TypeScript / Node.js – server-side HTTP services, networking fundamentals, clean typed code; REST/JSON API design – versioning, consistent error contracts, idempotency, pagination, and an API-as-contract mindset (OpenAPI); Relational data – schema design, migrations, and a data-integrity mindset; Asynchronous & queue-driven systems – background workers, job lifecycles, retries, idempotent processing; API security – token-based auth (OAuth/JWT), authorization and tenancy isolation, secure secret handling, “fail-closed” defaults, and awareness of industry baselines (e.g.

OWASP API Security Top 10); Test-forward development – comfortable driving work through unit, integration, and contract tests as a first-class part of building, not an afterthought; Hands-on AWS experience (mandatory) – must know the specifics of core AWS services (containers/compute, queuing, managed databases, secrets, load balancing). Given the short timeline and MVP nature, we prefer they not need to onboard onto a new cloud; Cloud-native delivery – building and shipping containerized services, infrastructure-as-code (Terraform ideal), CI/CD pipelines; Observability – structured logging, metrics, tracing, and audit trails; can debug production from telemetry.

Nice-to-haves: fintech or other regulated-domain experience · platform / API-gateway team background · leading a small delivery independently.