Full Stack Engineer

About Accountabl

Accountabl is building a modern expense management platform for growing companies, combining smart corporate cards, automated expense capture, and real-time financial controls into one seamless platform.

We build fintech infrastructure that powers how businesses spend, track, and control. As we scale, platform reliability, performance, and thoughtful engineering are critical to delivering a seamless experience.

We’re hiring a Full Stack Engineer to take ownership of core platform components and help shape the next phase of Accountabl’s evolution.

About The Role

This is a full-time, hybrid role based in London for a Full Stack Engineer. You’ll work closely with the Technical Lead and Product Team to build, maintain, and enhance Accountabl’s platform and integrations. From designing new features to strengthening backend services and APIs, you’ll contribute across the full development lifecycle.

We’re looking for someone who writes clean, scalable code, thinks about system reliability, and takes ownership from idea through to deployment.

If you enjoy building scalable fintech products and solving complex operational challenges, we’d love to hear from you.

What You'll Be Doing

• Designing, building, and maintaining secure, scalable backend and frontend components
• Contributing to the architecture and implementation of new product features
• Developing and maintaining API integrations with external systems
• Working on authentication flows, webhooks, and data synchronisation processes
• Collaborating with Product to assess technical feasibility and support feature testing
• Participating in sprint planning, retrospectives, and Agile ceremonies
• Writing unit and integration tests to ensure platform stability
• Supporting performance optimisation, monitoring, and bug resolution
• Maintaining clear documentation for APIs and technical processes
• Continuously identifying opportunities to improve automation, reliability, and efficiency

What You’ll Need

• 2–4 years of experience building production-grade applications
• Strong experience with JavaScript / TypeScript (full-stack), writing production code across frontend and backend
• Experience with React (React Native for mobile is a plus) and modern SPA frameworks
• Experience with NestJS or comparable structured backend frameworks such as .NET or similar
• Solid understanding of clean, reusable, maintainable code, separation of concerns, and scalable system design
• Experience building and consuming RESTful APIs and/or event-driven systems
• Experience working with PostgreSQL, strong SQL fundamentals, and comfort across raw SQL, query builders, and ORMs
• Comfort working in an Agile development environment
• Strong problem-solving ability, attention to detail, and ownership mindset
• Clear communication skills and ability to collaborate cross-functionally

Why Join Accountabl

You’ll work at the core of a growing fintech platform, building and improving systems that power real transactions for real businesses.

You’ll have ownership over meaningful parts of the codebase, from feature development to architectural decisions, rather than just shipping tickets.

You’ll collaborate closely with product and leadership, giving you influence over technical direction and the opportunity to shape how the platform evolves as we scale.