Senior AI Engineer — Build Production LLM Systems

Primis; Greater London; On-site; GBP 70,000 - 90,000; Full time

Job summary

A high-growth AI startup in the UK is seeking a Senior AI Engineer to design and implement LLM-powered systems that address real customer problems. This hands-on role requires strong skills in building AI systems and understanding ML fundamentals. Ideal candidates will enjoy switching between high-level design and low-level debugging, working on scalable AI orchestration, and collaborating with cross-functional teams. The company encourages underrepresented talent to apply and supports accessibility needs.

Qualifications

• Experience building and deploying non-trivial AI systems in production.
• Strong understanding of machine learning and deep learning fundamentals.
• Experience with LLMs, agents, RAG, or large-scale inference pipelines.
• Ability to move comfortably between research papers and production code.
• Curiosity, ownership, and a strong desire to keep improving.

Responsibilities

• Design and implement LLM-based systems and agentic workflows.
• Build and maintain evaluation frameworks to measure model performance.
• Develop scalable, asynchronous systems for AI orchestration.
• Work on RAG pipelines, multi-agent systems, and production LLM workflows.
• Collaborate closely with engineers, researchers, and product teams.
• Contribute to AI strategy and long-term technical direction.

Skills

Building and deploying AI systems

Understanding of ML and deep learning fundamentals

Experience with LLMs and large-scale inference pipelines

Switching between research and production code

Curiosity and ownership

Job description

A high-growth AI startup in the UK is seeking a Senior AI Engineer to design and implement LLM-powered systems that address real customer problems. This hands-on role requires strong skills in building AI systems and understanding ML fundamentals. Ideal candidates will enjoy switching between high-level design and low-level debugging, working on scalable AI orchestration, and collaborating with cross-functional teams. The company encourages underrepresented talent to apply and supports accessibility needs.