Senior Applied AI Engineer

Octopus was founded with a mission to use technology to accelerate us towards a low‑carbon future. That’s why we created Kraken – our own technology platform from scratch which now serves over 70 million households and is a core reason why Octopus is the number one energy supplier in the UK. We do it by hiring clever, curious, and self‑driven people, enabling them with modern tools and infrastructure and giving them lots of autonomy.

We have been using GenAI in live, customer‑facing environments since 2022, including one system that creates tens of thousands of high‑quality emails for our Energy Specialists, combining our deep knowledge of the energy industry and the Octo communication style with customer‑specific data from Kraken.

We are now looking for a Senior AI Engineer. You will take ownership of building and scaling the systems that allow Octopus teams to use Generative AI models (LLMs, RAG, agents). This may take the form of a platform, shared services, or other scalable infrastructure. You will work with a cross‑functional team to build out flagship AI projects and will continue to develop the best practice for how we work with AI at Octopus.

You’ll report into the Head of AI and work on developing solutions that genuinely move us closer to Net Zero in a company passionate about building great technology to change the way customers use energy. You’ll have wide open problems to solve, so you’ll need to be comfortable with ambiguity, figuring out an approach and validating it fast.

• Design and Develop AI Platform Services – Build reusable, scalable services that expose GenAI models, knowledge retrieval pipelines, and agent workflows to application teams.
• Knowledge Base Development – Build and maintain knowledge retrieval systems including embedding generation, chunking, and strategies for database management.
• AI Ops, evals and observability – Setting up frameworks for monitoring and evaluating AI output quality (relevance, accuracy, safety, drift, cost) and platform observability (latency, cost, usage).
• Centre of Excellence – Act as a centre of excellence for the whole business in the technical side of AI and LLMs usage, setting best practices and accelerating adoption.
• Context Engineering – Design systems for prompt assembly:
  Create prompt templates, system prompts and guidelines for platform users.
• Governance and Guardrails – Create governance layers for implementing PII redaction, prompt filtering etc.

• Deep Understanding of GenAI – 2+ years experience of working with LLMs and using techniques such as tool calling, agentic workflows, fine tuning and reinforcement learning.
• Data Product Development – 5+ years of experience building Python‑based applications and/or data products, with hands‑on work in data‑intensive and machine‑learning systems.
• GenAI Application Development – Hands‑on experience of building AI applications which have been successfully deployed into production.
• AI model evaluation and observability – Experience of different ways of evaluating AI models and applications. Implementing logging, tracing, and monitoring in systems.
• Context Engineering and Knowledge Grounding – Experience of optimising and grounding GenAI models and applications through prompt design, RAG and knowledge base integration.
• Software Development Practices – Strong grounding in Git, testing, CI/CD frameworks.
• Ability to thrive in a fast moving environment – Dealing with ambiguity, setting clear priorities, and translating ideas into actionable plans.

• Backend Development – Experience designing and building applications and services that encapsulate business logic, data and information flows and connect AI models into wider applications.
• Pipeline Design and Build – Experience integrating different types of databases and building and optimising data pipelines.
• Vector Databases and Knowledge Graphs – Familiarity with graph and vector databases such as Pinecone and Neo4J.
• Java script – Familiarity with Java script, particularly within backend build.

• Salary – Just ask us! On a call with one of our recruiters it is always covered so we can…