FinTech Low-Code API Engineer (Security & Scale)

Enfint; Amsterdam; On-site; EUR 75,000 - 95,000; Full time

Job summary

Enfint is seeking a senior backend engineer to design, build, and operate secure partner-facing APIs for financial institutions. You will own API design, contract testing, and scalable onboarding, while ensuring security, reliability, and excellent developer experience.

You will collaborate across teams, implement containerized services on AWS, and drive architecture and documentation from specification to delivery.

Qualifications

• Strong backend development experience with TypeScript and Node.js, focusing on robust HTTP services.
• Experience designing REST/JSON APIs with versioning, error contracts, idempotency, pagination, and OpenAPI.
• Proficiency with relational databases, schema design, migrations, and data integrity.
• Experience with asynchronous and queue-driven systems, background workers, retries, and idempotent processing.
• Security-focused API design, OAuth/JWT, tenancy isolation, and OWASP API Security guidance.
• Practice of test-forward development with unit, integration, and contract tests.

Responsibilities

• Expand the API surface with new endpoints, webhooks, and richer queries.
• Improve developer experience via clear contracts, docs, and sandbox environments.
• Harden APIs through rate limiting, secret rotation, tests, and security remediation.
• Scale multi-partner onboarding, tenant isolation, load testing, and caching.
• Enhance platform quality with SLOs, alerts, and resilience patterns.
• Deliver work from spec through design to tested delivery.
• Break down work into clear chunks and drive to completion.
• Author and refine specifications, acceptance criteria, and decision records.
• Oversee AI-assisted development output and ensure quality standards.

Skills

TypeScript

Node.js

REST APIs

OpenAPI

Relational DB

Async processing

OAuth/JWT

Testing

AWS

CI/CD

Observability

Technical writing

Tools

Docker

CI/CD tooling

Job description

Enfint is seeking a senior backend engineer to design, build, and operate secure partner-facing APIs for financial institutions. You will own API design, contract testing, and scalable onboarding, while ensuring security, reliability, and excellent developer experience.

You will collaborate across teams, implement containerized services on AWS, and drive architecture and documentation from specification to delivery.