Backend Engineer - API Development

Backend Engineer - API Development (TypeScript / Node.js) As a preferred supplier to one of our biggest Financial Client, I am seeking for a Backend Engineer - API Development (TypeScript / Node.js) for a position in Amsterdam, Netherlands. The successfully candidate is 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. Where you 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 environmentsHardening - rate limiting, secret rotation, contract testing, pen-test remediationScaling - repeatable multi-partner onboarding, tenant isolation, load/performance testing, cachingPlatform quality - SLOs, alerting, resilience patterns Ways of working: Independent and self-directing - takes a capability from spec → design → tested delivery without hand-holdingHelps 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 writerComfortable 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 multiplierQuality-first and pragmatic - treats security, testing, and observability as ship-blocking, while favoring simple solutions over over-engineering Core skills requirement: Modern backend development in TypeScript / Node.js - server-side HTTP services, networking fundamentals, clean typed codeREST/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 mindsetAsynchronous & queue-driven systems - background workers, job lifecycles, retries, idempotent processingAPI 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 afterthoughtHands-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 pipelinesObservability - structured logging, metrics, tracing, and audit trails; can debug production from telemetry Nice-to-haves: fintech or other regulated-domain experienceplatform / API-gateway team backgroundleading a small delivery independently Contract: 12+ month Rates: Excellent Location: Amsterdam Interview: 2 stages Nick Chinweerapunt Account Manager Gazelle Global Consulting Tel +31 85 111 0171 Tel +44 203 588 7747 Mob +44 7377 403 773 nick@gazellegc.com