Senior Full Stack Software Engineer (AWS/NodeJS/React)

About the role

We are looking for a senior full‑stack software engineer to join a fast‑growing FinTech start‑up developing credit card, personal loan and insurance products. The role is hybrid, based in Central London, and offers a day rate of £400 inside IR35.

Key responsibilities

• Design, develop and maintain advanced web and mobile applications.
• Collaborate with cross‑functional teams to define, design and ship new features.
• Guide and mentor junior engineers, conduct code reviews and improve development processes.
• Optimize components for performance across browsers and devices.
• Write automated tests and ensure high‑quality code.
• Troubleshoot, debug and enhance system performance.

Required profile

• Proven experience as a senior full‑stack developer, preferably in a start‑up environment.
• Strong portfolio of back‑end‑leaning projects.
• Degree in Computer Science or related field, or equivalent experience.
• Excellent problem‑solving and communication skills.

Required skills

• AWS (including Lambda and serverless architecture)
• Node.js
• TypeScript and JavaScript
• React (with Next.js) and React Native
• Terraform for infrastructure as code
• RESTful API design
• Automated testing frameworks such as Jest or Mocha
• CI/CD pipelines, code signing and deployment to App Store and Google Play
• Cloud messaging APIs and push‑notification handling

What we offer

• £400 day rate (inside IR35)
• Hybrid working model – 1‑3 days per week in Central London
• Opportunity to shape a revolutionary FinTech product