Backend Engineer API Development | Fintech Scale-up Backed by a Major Bank | AWS & TypeScript
A fast-growing fintech scale-up in the business financing space, backed by a major bank, is looking for an independent backend engineer to help build, harden and scale its secure API platform. The internal lending logic is already covered by the in-house team, so this role is pure backend and API craft: growing the partner-facing surface, tightening security, and getting the platform ready to onboard more partners at scale.
It is a deliberately simple, well-structured codebase, held to the standards you would expect from a financial institution. You will work with a modern TypeScript and Node.js stack on AWS, and the project leans heavily on agentic, AI-assisted development, so someone who can direct and review that kind of output well will genuinely multiply the team’s output rather than just add a pair of hands.
About the role
You will take ownership of the partner-facing API platform end to end, from spec and design through to tested, production-ready delivery. Rather than executing a backlog of tickets, you will help break down the work, sequence it, and drive it to a clear done, working closely with a small, senior team.
- Grow the API surface cleanly: new endpoints, webhooks and callbacks, and richer querying options for partners.
- Improve the developer experience for partners integrating with the platform: clear contracts, published OpenAPI specs, integration docs and sandbox environments.
- Harden the platform: rate limiting, secret rotation, contract testing and remediation of pen-test findings.
- Build for scale: repeatable multi-partner onboarding, tenant isolation, load and performance testing, and caching.
- Raise platform quality: SLOs, alerting and resilience patterns, backed by strong observability.
Who are you?
- Strong hands-on backend development experience in TypeScript and Node.js, building server-side HTTP services with clean, typed code.
- Solid REST/JSON API design skills: versioning, consistent error contracts, idempotency, pagination and an API-as-contract mindset using OpenAPI.
- Mandatory hands-on AWS experience with core services such as containers or compute, queuing, managed databases, secrets and load balancing.
- A test-forward mindset, comfortable driving work through unit, integration and contract tests as part of building, not as an afterthought.
- Practical knowledge of API security: token-based auth (OAuth/JWT), authorization and tenancy isolation, and secure secret handling.
About Levy Global
Levy Global is a specialist consulting and recruitment partner supporting technology professionals across the UK, Europe and North America. Since 2000, we have helped people build careers across data and AI, cloud, cybersecurity, infrastructure, enterprise systems, software development and business change.
We work with scale-ups and global organisations, connecting talented people with projects and roles where they can make an impact. Our strength has always been the way we support people, from first conversation through to placement, onboarding and beyond.
