Principal Backend Engineer

Principal Backend Engineer | London | Hybrid

We’re working with a scaling FinTech looking for a Principal Backend Engineer to lead the technical evolution of their backend platform.

This is a deeply technical, hands-on role for someone who enjoys making difficult architectural decisions, setting a high engineering bar and building systems that can scale with confidence.

What you’ll be working with

• TypeScript / Node.js / NestJS
• AWS & Docker
• MySQL / relational databases
• High-volume data processing and distributed workflows
• Typed APIs and integration contracts
• Event-driven architecture and reliable processing
• Observability, resilience and operational excellence

What you’ll be doing

• Own the technical direction and architecture of the backend platform
• Design scalable systems capable of handling millions of records and events
• Establish clear boundaries between application, data and delivery layers
• Build robust, well-typed APIs and processing workflows
• Improve reliability through idempotency, retries, observability and failure isolation
• Lead technical design reviews and raise engineering standards
• Mentor engineers through code reviews and technical pairing
• Drive improvements across scalability, security and maintainability
• Use AI-assisted and agentic engineering tools to improve development, testing and technical workflows

City of London, hybrid working, £120K - £150K , equity

Interviews taking place 21st October onwards