Senior Product Engineer

Senior Product Engineer London (Hybrid) Up to £140,000 + EquityLooking to make a genuine impact at an early-stage AI startup? This is an opportunity to join a well-funded business as one of its first engineering hires, taking ownership of a product already being tested by major enterprise customers. The Company This AI startup is building a behavioural intelligence platform that helps financial services organisations better understand customer behaviour and decision-making. Backed by significant early-stage investment, they are working with large enterprise clients and moving from proof-of-concept projects towards commercial deployment. With a small, highly capable team, they are focused on building scalable AI products with real-world impact. The Role You will take ownership of product development, helping to build and scale an AI-powered platform from an early stage.Responsibilities include:

• Building LLM-enabled products and features used by enterprise customers

• Designing and developing backend services, APIs, and platform capabilities

• Owning RAG workflows and AI application architecture

• Managing evaluation frameworks, testing, monitoring, and quality standards

• Optimising LLM performance, scalability, and cost efficiency

• Working closely with product leadership and customers to shape the roadmap

• Establishing engineering best practices across development and deployment Your Skills & Experience

• Strong experience as a Product Software Engineer

• Proven track record building and shipping an LLM-based product from 0 to 1

• Experience owning architecture, product decisions, and implementation

• Strong backend engineering experience with API-first products

• Hands-on experience with RAG and production AI systems

• Understanding of token usage, model evaluation, and cost optimisation

• Ability to operate autonomously in a startup environment

• Strong communication and stakeholder management skills Desirable:

• Experience with Node.js, TypeScript, and React

• Computer Science background

• Experience within AI startups, technology companies, or financial services What They Offer

• Salary up to £140,000

• Meaningful equity package

• Hybrid working in London

• Significant ownership and autonomy

• Opportunity to shape the engineering culture and technical direction

• Direct exposure to founders and business leadership How to Apply Apply today to learn more about this opportunity to build and scale cutting-edge AI products within a fast-growing startup.