low-code developer for financial APIs

The team builds and operates secure partner-facing APIs for financial institutions, focusing on security, reliability, testing, developer experience, scalability, and platform quality.

• Grow the API surface with new endpoints, webhooks/callbacks, and richer querying;
• Improve developer experience through clear contracts, published API specifications, integration documentation, and sandbox environments;
• Harden APIs through rate limiting, secret rotation, contract testing, and penetration-test remediation;
• Scale repeatable multi-partner onboarding, tenant isolation, load and performance testing, and caching;
• Improve platform quality through SLOs, alerting, and resilience patterns;
• Take capabilities from specification through design and tested delivery independently;
• Break down, sequence, and drive bodies of work to a clear completion;
• Write and work from specifications, acceptance criteria, and decision records;
• Direct and review AI-assisted and agentic development output;
• Maintain security, testing, and observability as release-blocking quality standards while favoring simple solutions.

• Modern backend development experience with TypeScript and Node.js, including server-side HTTP services, networking fundamentals, and clean typed code;
• REST/JSON API design experience with versioning, consistent error contracts, idempotency, pagination, and an API-as-contract mindset using OpenAPI;
• Relational data experience, including schema design, migrations, and data integrity;
• Experience with asynchronous and queue-driven systems, background workers, job lifecycles, retries, and idempotent processing;
• API security knowledge, including OAuth/JWT authentication, authorization, tenancy isolation, secure secret handling, fail-closed defaults, and OWASP API Security Top 10 awareness;
• Test-forward development experience with unit, integration, and contract tests;
• Hands-on AWS experience with containers/compute, queuing, managed databases, secrets, and load balancing;
• Experience building and shipping containerized services, infrastructure as code, and CI/CD pipelines;
• Observability experience with structured logging, metrics, tracing, and audit trails, including debugging production from telemetry;
• Ability to work independently and self-direct delivery without hand-holding;
• Clear and concise technical writing skills;
• Must currently live in the Netherlands;
• Nice to have: fintech or other regulated-domain experience, platform or API-gateway team background, leading a small delivery independently.

• Contract role for 36 hours per week;
• Start: 07 September 2026;
• End: 01 June 2027;
• Possible extension;
• ZZP is allowed.