Jobs in London, United Kingdom

Job Title: Principal AI Engineer
Employer: The Portfolio Group
Location: London, United Kingdom
Salary:
Employment Type: Permanent
Reference Number: 23643_224544909

Principal AI Engineer London Excellent Salary +Benefits

Join an award‑winning, internationally recognised International B2B Consultancy organisation as a Principal AI Engineer, where you will play a pivotal role in shaping and delivering production grade generative AI capabilities.

This is a senior; hands‑on engineering role focused on building the intelligence layer of advanced AI products. You will design and implement Retrieval‑Augmented Generation (RAG) pipelines, agentic workflows, and robust evaluation frameworks that ensure AI systems are accurate and aligned with real‑world business needs.

Reporting to the Director of AI, you will translate strategy and architecture into high‑quality implementations, working closely with AI Platform Engineering to ensure solutions are scalable, maintainable, and production ready.

1. Design, build, and train production‑grade generative AI systems.
2. Implement robust RAG pipelines that effectively leverage proprietary and domain‑specific content.
3. Develop agentic and workflow‑based AI patterns with a focus on determinism, quality, and maintainability.
4. Apply model adaptation techniques prompting, fine‑tuning, distillation‑to optimise quality, latency, and cost.
5. Establish strong experimentation and evaluation practices to measure correctness, faithfulness, and robustness.
6. Act as a technical authority, providing hands‑on leadership, mentoring, and code‑level guidance to AI engineers.
7. Collaborate closely with platform, product, and delivery teams to move AI capabilities from experimentation into production.
8. Contribute to advanced retrieval techniques, including Graph‑RAG and structured knowledge representation, where they add value.

1. Strong Python proficiency for production‑grade AI development, with hands‑on experience using LlamaIndex, LangChain, and LangGraph.
2. Proven experience building Retrieval‑Augmented Generation (RAG) systems; Graph‑RAG experience is a plus.
3. Practical experience with model adaptation techniques, including prompting, fine‑tuning, instruction tuning, or knowledge distillation.
4. Solid understanding of evaluation and experimentation for generative AI, focused on correctness, faithfulness, and robustness.
5. Demonstrable experience owning technical design and delivery of complex AI, ML, or data‑driven systems in production environments.
6. Experience operating as a senior AI engineer or technical lead, balancing experimentation with production delivery and communicating effectively across teams.

This is a progressive career opportunity to work at the cutting edge of Generative AI model deployment, where your work directly shapes customer‑facing products and business innovation. You will have real ownership, technical autonomy, and the backing of a world‑class leadership team committed to building AI that delivers measurable value.