Founding AI Platform Engineer — Stealth AI Startup (Energy Sector)

Founding AI Platform Engineer for a Stealth Start-Up Up to £120k + Equity On-Site We are working with a stealth, revenue-generating AI startup that is building the platform for the energy transition. The business is backed by strong early investors, including individuals behind Lovable and Black Forest Labs, as well as angels from Google DeepMind, alongside senior executives from the energy industry.The company is building the AI platform for developing, financing, transacting and operating renewable energy assets, starting with legal due diligence. The platform reads the data room, structures the asset, runs the legal checks, and surfaces what is missing, allowing lawyers to work inside the platform to resolve ambiguity and produce the final report. This is an established product with active clients and meaningful revenue, not an early-stage concept.The company is now hiring a Founding Engineer to own three connected areas of the business:Production AI - agent architecture, context engineering, retrieval, tool use, citations, evaluation, tracing, reliability and cost.Developer platform — the development stack, repository architecture, local, staging and production workflows, testing, CI/CD, observability and deployments.AI-native engineering — the rules, skills, context, guardrails and automation that allow coding agents to work safely and effectively across the codebase.This is a rare opportunity to shape how a growing engineering team works, both in terms of the product being built and the way engineers and AI agents collaborate on that codebase.The stack includes Python, FastAPI, React, TypeScript, PostgreSQL, Temporal and LLM tooling.We are looking for someone with strong production judgment, genuine ownership over decisions and outcomes, and the ability to move comfortably across agents, backend, infrastructure and product.Prior experience with this exact stack is not essential, but a track record of building dependable systems for real users is important, as is the willingness to raise problems early and challenge assumptions where needed.This role is based in London, working from the office five days a week with flexibility when required. Candidates should have at least four years of professional engineering experience and existing right to work in the UK.