Principal AI Engineer | Up to £220k + Equity | London, Hybrid
We’re working with a well-funded frontier AI company building the systems used to train, evaluate and improve advanced AI agents.
They’re hiring a Principal AI Engineer to take ownership across model training, post-training, RL, evaluation and agent infrastructure. This is a hands, on IC role with real influence over technical direction.
Responsibilities
- Lead major AI and research-engineering initiatives end to end
- Build and improve training, fine-tuning and post-training pipelines
- Develop evaluation systems, agent harnesses and feedback loops
- Own technically ambiguous problems from experimentation through to production
- Set technical direction while remaining close to code and models
Requirements
- Strong experience with LLM training, post-training, RL or evaluation
- Excellent software engineering fundamentals, ideally Python
- Track record of solving difficult AI problems in production
- Experience within a top-tier AI lab, technology company or high-bar startup
- Strong academic background in Computer Science, ML, Mathematics or a related STEM field
- Evidence of operating at Principal or equivalent senior IC level
Location
London, typically 2 days per week onsite.
Package
Up to £220,000 base + meaningful equity.
#J-18808-LjbffrVacancy posted 3 days ago
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