Full Stack Software Engineer – FinTech Startup

About the role

We are looking for a senior‑level Full Stack Software Engineer to join a fast‑growing FinTech start‑up that is launching credit cards, personal loans and insurance products. The role is hybrid, with 1‑3 days a week in our Central London office, and offers a competitive day rate within an IR35‑compliant contract.

Key responsibilities

• Design, develop and maintain advanced web and mobile applications.
• Collaborate with product, design and other engineering teams to define, design and ship new features.
• Guide and mentor junior engineers, providing code reviews and technical leadership.
• Optimize components for performance across a wide range of devices and browsers.
• Write automated tests and ensure high‑quality code delivery.
• Troubleshoot, debug and improve system performance.
• Stay current with emerging technologies and best practices.

Required profile

• Proven experience as a senior full‑stack developer, preferably with a back‑end focus.
• Strong portfolio of projects using Node.js and serverless architectures.
• Experience in a start‑up environment and a degree or equivalent in Computer Science or Engineering.
• Excellent problem‑solving abilities and strong communication skills.

Required skills

• AWS (including Lambda)
• Node.js
• TypeScript & JavaScript
• React.js & Next.js
• React Native (beneficial)
• Terraform
• RESTful APIs
• Automated testing frameworks (Jest, Mocha)
• CI/CD pipelines and cloud messaging APIs

What we offer

• £400 day rate (inside IR35)
• Hybrid working model (1‑3 days onsite)
• Opportunity to shape innovative financial products.