Senior AI Engineer

Octopus Energy’s proprietary Kraken platform powers over 70 million households and underpins our mission to accelerate the planet’s transition to a low-carbon future. After running generative- AI systems in production since 2022, we are scaling our AI capability and need a Senior AI Engineer to own the platforms, services and infrastructure that let every Octopus team harness large language models, retrieval-Augmented generation and autonomous agents.

What you’ll do

• Design and build AI platform services: expose LLMs, RAG pipelines and agent workflows through reusable, scalable APIs and libraries.
• Develop and maintain knowledge bases: implement embedding generation, intelligent chunking, vector storage and refresh strategies.
• AI Ops, evaluation & observability: create dashboards and automated tests that track relevance, accuracy, safety, drift, cost, latency and usage.
• Context engineering: craft prompt templates, system prompts and user guidelines that keep responses on-brand and fact-grounded.

What you’ll bring

• Deep, hands-on experience with LLMs and GenAI tooling.
• Strong Python development background shipping data-intensive or ML products.
• Proven work on model evaluation, logging, tracing and monitoring.
• Expertise in grounding GenAI via prompt design, RAG and knowledge-base integration.
• Solid software craft: Git, automated testing, CI/CD.
• Comfort navigating ambiguity, setting priorities and delivering iteratively.

Nice to have

• Production GenAI apps featuring tool-calling, agents, fine-tuning or RL.
• Backend design experience connecting AI models to larger business services.
• Data-pipeline optimisation across heterogeneous databases.

You will report to the Head of AI, collaborate with cross-functional squads and work on flagship projects that directly advance Octopus Energy’s net-zero goals. Flexible salary, hybrid London base and award-winning culture included.