Principle HR

Principle HR in London is seeking a Research Engineer to advance AI research and ML systems. The role blends hands-on engineering with rigorous experimentation on large models, reinforcement learning, synthetic data, and multi-agent setups. You will work within a world-leading technology organization, contributing to cutting-edge infrastructure and research initiatives in a fast-moving, ambiguous environment where priorities evolve rapidly.

Research Engineer - Machine Learning & Generative AI 12-month contract £64,000-£71,000 London Hybrid - 3 days onsite We're hiring a Research Engineer to join a world-leading technology organisation working at the forefront of AI and machine learning research. This is a rare opportunity to be deeply embedded within a research team, contributing directly to cutting-edge work around large AI models, reinforcement learning, synthetic data and multi-agent systems. You'll combine hands on engineering with research, building and experimenting with ML systems, developing robust research infrastructure and working alongside researchers on complex, rapidly evolving problems. Non negotiable skills: 2+ years' hands-on Machine Learning/AI experience - including ML, artificial intelligence, recommendation systems or pattern recognition. Strong Python programming skills Experience developing ML models at scale Experience running complex experiments with large AI models and datasets. Strong understanding of the scientific/research process and the ability to investigate why approaches succeed or fail. Comfortable operating in a fast-moving, highly ambiguous research environment where priorities can change quickly. Experience with PyTorch, LLMs, LLM post-training, reinforcement learning, generative AI or multi-agent systems would be particularly valuable. A research-focused Master's or PhD in ML/AI is advantageous but not essential. Deadline for this role is Monday the 14th of December.

Principle HR is seeking a senior data engineer to own end-to-end data infrastructure for a global tech company. You will design and scale ETL pipelines and data models that measure marketing performance across apps, with leadership from architecture to execution and encouragement to use AI tools. The role is a 6-month contract inside IR35, fully remote within the UK, with weekly payments through Principle HR. Candidates based in the UK with right to work are required.

Principle HR in London is seeking a Senior Research Engineer to join a world-leading technology organisation, focusing on AI and machine learning research. You'll be embedded in a cutting-edge team working on LLMs, RL, synthetic data, and multi-agent systems. This unusually research-heavy engineering role involves building robust infrastructure to support experiments and deploying production-quality code at scale.

Senior Research Engineer - Machine Learning & Generative AI 12-month contract £81,000-£90,000 London Hybrid - 3 days onsite We're hiring an experienced Senior Research Engineer to join a world-leading technology organisation working at the frontier of AI and machine learning research. This is an unusually research-heavy engineering opportunity. You'll be embedded directly within a cutting-edge AI research team, working on areas including large language models, reinforcement learning, synthetic data, multi-agent systems and AI agents, while also building the robust infrastructure needed to support complex research experiments. Non negotiable skills: 5-7 years' relevant experience, with strong hands-on Machine Learning/AI expertise. Strong Python programming skills - a core non-negotiable. Proven experience developing machine learning models at scale, ideally within a leading technology company, AI research lab or similarly sophisticated environment. Experience writing production-quality software and running complex experiments involving large AI models and datasets. Strong scientific/research mindset - able to investigate not just whether an approach works, but why. Comfortable working at pace in a highly ambiguous research environment where priorities can change rapidly. Experience with PyTorch, LLMs, LLM post-training, reinforcement learning, generative AI or multi-agent systems would be particularly valuable. A research-focused Master's or PhD in AI/ML is advantageous but not essential. Deadline for this role is Monday the 14th of September.