🚀 Founding Product Engineer | Up to £200,000 + Meaningful Equity 📍 King's Cross, London | Full-time | On-site (5 days/week) ⚠️ PLEASE READ BEFORE APPLYING ✅ You must already have the unrestricted right to work in the UK. ❌ Visa sponsorship is NOT available for this position. ❌ Applications requiring current or future sponsorship cannot be considered. 🏢 This is an office-based role in King's Cross, London (5 days per week). TechTree is partnering with an exciting AI startup to hire a Founding Product Engineer who wants to build category-defining technology from day one. This isn't a role where you'll simply pick up tickets. You'll work directly with experienced founders, shape both the product and engineering culture, own major technical decisions, and build software used by leading enterprise customers. If you enjoy taking ideas from concept to production and thrive in fast-moving environments, this is a genuinely rare opportunity. 💷 What you'll get • Up to £200,000 base salary • Meaningful equity package • Founding team influence from day one • Work directly alongside exceptional founders • AI-first engineering environment • Premium AI tooling and API budgets • Daily team lunches, speciality coffee and a fantastic King's Cross office 🛠️ You'll be responsible for • Owning features from idea through to production • Building modern full-stack applications using TypeScript, React and Node.js • Designing APIs, data models and AI-powered product experiences • Working directly with customers to solve real-world problems • Shipping high-quality software quickly and responsibly • Helping define the future engineering culture of the company ✅ We're looking for someone with • 6+ years of commercial software engineering experience • Strong TypeScript, React and Node.js expertise • Experience building products from 0 → 1 • Production experience integrating LLMs or AI features • An AI-first workflow using Claude Code, Copilot or similar • Strong product thinking and engineering judgement • High ownership, autonomy and excellent communication skills ⭐ Bonus if you have • Experience at high-bar technology companies • Built impressive side projects, startups or open-source projects • Conference talks, technical publications or research • Experience building AI-native SaaS products This is one of those opportunities where your work won't just contribute to the product—it will define it. If you love ownership, building with AI, moving fast and solving genuinely difficult engineering challenges, we'd love to hear from you. 📩 Apply here: https://jobs.techtree.dev/job/2857cf56-3849-4601-9cdd-39c55a5072c9?tp=04b74924-4168-417c-91a8-2ec52e5b28a1