Senior Full Stack AI Engineer

Senior Full Stack Engineer (AI Product) Hybrid (London) | £80,000 - £110,000 + equity I'm working with a fast-growing, VC-backed AI startup that is transforming a document-heavy, high-value workflow for B2B teams. The product is already live with paying customers who report dramatic time savings, and the company is entering a major growth phase. The team is small and highly focused, and this is a chance to join early, own meaningful parts of the product, and help shape both the architecture and the product direction. What you'll be doing

• Building core platform and AI features end to end, from polished React frontends to robust Python backend services
• Designing and improving multi-step agentic workflows, including context engineering and agent evaluation
• Making key decisions on infrastructure, data models and system design as the platform scales
• Championing engineering quality through testing, code review, CI/CD and monitoring
• Working directly with product, design and customer-facing teams to ship features customers love What they're looking for
• 4 - 8+ years of full-stack experience with React, TypeScript, Node and Python
• Hands-on experience building AI products, ideally with LangChain, LangGraph and LangSmith or similar tooling
• Experience with context engineering and evaluating agents
• Comfort owning features from design through to deployment
• Previous startup experience Why join
• Genuine autonomy: you'll largely decide what you work on
• A fast track into senior responsibilities
• Hard, interesting AI problems in a product with proven demand
• Equity in a company with strong momentum If this sounds like you, send me a message at mmatysik@trg-uk.com or apply with your CV!