AI Researcher, LLMs

About This Opportunity

We are representing a confidential quantitative trading firm seeking an AI Researcher with deep expertise in large language models. This role sits within a specialized AI research group responsible for building production LLMs from the ground up—pretraining, post-training, and deployment—that directly support trading and research operations. Our client maintains state-of-the-art research infrastructure with exceptional GPU resources and a lean, high-impact team structure.

This is a London-based position for someone who wants to work on frontier LLM capabilities with immediate real-world application. You'll have significant autonomy to identify high-impact directions while being supported by world-class engineering and infrastructure teams.

Responsibilities

• Design and execute large-scale LLM training runs, including tokenizer development, dataset curation and mixing strategies, and pretraining architecture decisions
• Lead post-training efforts including supervised fine-tuning and reinforcement learning approaches to optimize models for specialized use cases
• Develop rigorous evaluation frameworks and statistical methods to measure model performance and guide development decisions
• Optimize inference systems and deploy models into production environments supporting live workflows
• Drive frontier capability improvements through novel approaches rather than adapting existing recipes
• Collaborate across research, engineering, and end-user teams to ensure models deliver measurable business impact

What We're Looking For

• Two or more years of hands-on experience training, post-training, or evaluating LLMs at scale
• Direct experience with at least one of: large-scale pretraining, post-training (SFT, RL), LLM evaluation design and statistical analysis, or distributed training/inference systems
• Strong research taste: ability to identify promising directions, design ablations that inform decisions, and update beliefs based on empirical evidence
• Excellent engineering skills valued, particularly: GPU kernel development, lower-level PyTorch internals, or published contributions to frontier-scale LLM research
• Track record of shipping impactful ML systems, not just experimental research
• Ability to work independently in a small team environment with minimal bureaucracy

How We Work With You

Candidates apply directly through Get A Job.ai. Our recruiting team will conduct an initial screening to understand your background and confirm fit for this role. We then coordinate your interview process with our client, providing guidance and feedback throughout. Please do not attempt to contact the employer directly—all communication should flow through our talent team to ensure a smooth process for everyone involved.

Pay

Pay information was not provided for this listing. Compensation details will be discussed during the screening process with our recruiting team.

Equal Opportunity

Get A Job.ai is committed to inclusive hiring practices. We welcome applications from candidates of all backgrounds and work with our clients to ensure fair and equitable recruitment processes.