Senior Full Stack AI Engineer

Senior Full Stack Engineer (AI Product)Hybrid (London) | £80,000 - £110,000 + equityI'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 doingBuilding core platform and AI features end to end, from polished React frontends to robust Python backend servicesDesigning and improving multi-step agentic workflows, including context engineering and agent evaluationMaking key decisions on infrastructure, data models and system design as the platform scalesChampioning engineering quality through testing, code review, CI/CD and monitoringWorking directly with product, design and customer-facing teams to ship features customers loveWhat they're looking for4 - 8+ years of full-stack experience with React, TypeScript, Node and PythonHands-on experience building AI products, ideally with LangChain, LangGraph and LangSmith or similar toolingExperience with context engineering and evaluating agentsComfort owning features from design through to deploymentPrevious startup experienceWhy joinGenuine autonomy: you'll largely decide what you work onA fast track into senior responsibilitiesHard, interesting AI problems in a product with proven demandEquity in a company with strong momentumIf this sounds like you, send me a message at mmatysik@trg-uk.com or apply with your CV!