Staff AI Engineer - Stealth Start-up - London

🚀 Staff AI Engineer | Stealth Mode AI Start-up | London | Up to £200k Oliver Bernard have partnered with a stealth-mode start-up in the AI & Research space, who are looking for a Staff AI Engineer to join the team and work on some genuinely challenging problems across LLMs, reinforcement learning and agentic systems.This is a hands-on research + engineering role, where you’ll be involved in:🧠 LLM training & fine-tuning – including reinforcement learning and post-training🔄 Evaluation & feedback loops – building systems to continuously assess and optimise models🤖 Agent development – designing and building sophisticated AI agents🔬 AI research – exploring LLM training, RL, evaluation and optimisation techniques💻 Software engineering – applying strong engineering fundamentals to complex AI problemsWhat they’re looking for:Strong experience working with LLMs and/or foundation modelsDeep experience with training, fine-tuning, RL or post-trainingStrong background in model evaluation and optimisationExperience building AI agents / agentic systemsExcellent software engineering fundamentalsA strong track record in AI research and solving technically complex problems📍 London – 2 days hybrid💰 Up to £200kIf you’re a Staff-level AI Engineer who wants to work at the intersection of cutting-edge research and production engineering, apply below for more information. London | Stealth | Staff AI Engineer