Senior AI Product Engineer

Senior AI Product Engineer up to £140,000 London (Hybrid) This is a fantastic opportunity to join an early-stage AI startup as one of its first engineering hires, taking ownership of a cutting-edge behavioural AI platform that is transforming how companies understand and engage with their customers. THE COMPANY: Our client is developing technology that helps their clients better understand not just what customers do, but why they make decisions. Their platform combines behavioural science and AI to provide actionable customer intelligence, enabling organisations to improve marketing, communications, customer support, and engagement strategies. THE ROLE: You will become the first senior individual contributor engineering hire, working closely with the VP of Product Engineering to build and scale the product from the ground up. Key responsibilities include: * Building and shipping AI-powered products end-to-end using LLM technologies. * Owning and scaling the retrieval-augmented generation (RAG) and AI application layer. * Developing secure, production-grade systems including guardrails, evaluation frameworks, monitoring, caching, and token cost optimisation. * Working across the stack, including backend services, APIs, cloud infrastructure, and selective frontend development. * Establishing engineering best practices around testing, delivery, architecture, and code quality. YOUR SKILLS AND EXPERIENCE: You will bring strong capability in: * Building and scaling production LLM-enabled products from 0-to-1. * Full-stack software engineering with strong backend expertise. * Product ownership, architecture, and independent decision-making. * Modern technologies including TypeScript, Node.js, React, PostgreSQL, AWS, and API-first architectures. * LLM evaluation, token optimisation, cost management, monitoring, and deployment best practices. - THE BENEFITS: You will receive a salary of up to £140,000 depending on experience. HOW TO APPLY: Please register your interest by sending your CV to Molly Bird via the apply link on this page.