low-code developer for financial APIs

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

Описание

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

Задачи

• 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.

Требования

• 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.

Условия

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