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.

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.

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.

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 Type Script, Node.js, React, PostgreSQL, AWS, and API-first architectures.
• LLM evaluation, token optimisation, cost management, monitoring, and deployment best practices.

You will receive a salary of up to £140,000 depending on experience.