Backend Developer

Backend Engineer – API Development Help build the secure API platform behind a growing financial services organization. You will join a fintech environment where speed and simplicity meet the security, reliability and quality standards of a financial institution. The platform enables partners to integrate business-financing services directly into their own products. This is a hands-on backend role for someone who can take a capability from specification to production. You will not simply execute tickets. You will shape solutions, structure the work and deliver reliable APIs that external partners can confidently build on. What you’ll work on: 🔌 Expand the API platform Design new endpoints, webhooks and callbacks while improving querying, versioning and error handling. 🧑 💻 Improve the developer experience Create clear API contracts, OpenAPI specifications, integration documentation and sandbox environments. 🔐 Strengthen security Implement rate limiting, OAuth/JWT authentication, authorization, tenant isolation and secure secret management. You will also resolve findings from penetration tests and apply OWASP API Security principles. 📈 Prepare the platform to scale Support repeatable partner onboarding, asynchronous processing, caching, load testing and resilient multi-tenant services. 🛠️ Raise platform quality Build testing, observability and reliability into every release through contract tests, structured logging, metrics, tracing, alerting and SLOs. You bring solid experience with: TypeScript and Node.js for server-side applicationsREST and JSON API designOpenAPI and contract-first developmentOAuth, JWT and API authorizationRelational databases, schema design and migrationsBackground workers, queues, retries and idempotent processingUnit, integration and contract testingContainerized services and CI/CD pipelinesInfrastructure as code, ideally TerraformLogging, metrics, tracing and production troubleshootingHands-on AWS experience is essential. You should be comfortable working with core AWS services for compute or containers, queues, managed databases, secrets and load balancing.Experience in fintech, another regulated environment or an API platform team is useful, but not required. How you work You are independent without becoming isolated. You can turn a specification into a sound design, break the work into manageable steps and drive it through testing to production. You write clearly, document decisions and treat security, testing and observability as part of the product rather than follow-up work. You favour simple, maintainable solutions over unnecessary complexity. The engineering environment makes extensive use of AI-assisted and agentic development tooling. You do not need to accept generated output blindly. You should know how to direct it, review it critically and take responsibility for the final result. Interested? Get in touch to discuss the team, project and working arrangements.