Principal / Senior Backend Engineer — Platform & Legacy Systems

We are looking for an experienced backend engineer to take ownership of an established platform, strengthen its reliability and lead its gradual modernisation while supporting ongoing delivery.

What you’ll do:

• Map and document backend services, queues and integrations. • Lead incremental refactoring supported by thorough testing. • Support core banking migration where existing services interact with the ledger. • Improve audit logging, monitoring and observability. • Guide engineering teams working with legacy services and support safe production releases.

What you’ll bring:

• At least 8 years of backend engineering experience. • Proven experience improving a large production codebase. • Strong TypeScript and Node.js skills; NestJS experience is preferred. • Production experience with MongoDB and PostgreSQL, including live data migrations. • Experience with RabbitMQ or similar messaging systems. • Strong testing practices and experience setting technical direction across teams.

Experience in fintech or banking, AWS, and canary or blue-green deployments would be an advantage.

This is a hands-on individual contributor role reporting to the Head of Engineering. Strong Senior engineers and candidates operating at Staff or Principal level are welcome.