Integration Developer (Node.js, TypeScript on AWS)

We are seeking an Integration Developer to build a containerised gateway service on AWS, using Node.js, TypeScript and Fastify on ECS Fargate. The service routes all transactional email from commerce and order management systems to a new email service provider. The developer will build:

a pass-through API

a backward-compatible API that converts legacy requests and responses using configurable mappings, so new campaigns can be added without a code release

The role covers idempotent processing, retry and failure handling, audit logging, event publishing and tracing, with security, resilience and observability built into the application. Development is OpenAPI-first, uses AI-assisted coding tools and is checked with contract tests built from real traffic. The developer will work closely with the architect, DevOps and QA on a fast build.

• Strong hands-on Node.js and TypeScript backend development, including Fastify (or a similar framework), asynchronous programming, REST/JSON APIs, validation and structured error handling.
• Working experience with AWS SDK integrations: DynamoDB, Secrets Manager, SQS/DLQ, and containerised deployment to ECS Fargate.
• Practical AI-assisted application development using an approved coding assistant: supplying contract context, iterating on generated code and verifying correctness with tests.
• API integration and transformation, legacy contract compatibility, token-based authentication and configurat