Senior Python Engineer - Contract - Outside IR35

We are hiring a Senior AI Engineer to join a team responsible for recommendation systems across web and mobile, working on a key AI-driven product, the AI Stylist.

This is a production-focused role. The AI Stylist is already live to customers and expected to scale significantly, with a large backlog of enhancements and increasing demand.

This is a hybrid position where 3 days per week are expected onsite in central London.

About the Role

You will join the Recommendations team, contributing to the AI Stylist experience, an AI-powered product that combines conversational interfaces with recommendation capabilities.

The work sits at the intersection of engineering and AI, focused on improving relevance, quality, and reliability in a live, customer-facing system.

You will collaborate closely with engineers, data scientists, and product stakeholders to evolve the system and support its rapid growth.

What You’ll Be Doing

• Building and evolving AI-powered services using Python

 • Designing and implementing evaluation frameworks for LLM-based systems

 • Improving output quality through structured evals rather than purely code changes

 • Applying techniques such as LLM-as-a-Judge to assess response and recommendation quality

 • Working with non-deterministic systems and iterating based on real-world behaviour

 • Integrating AI services into a broader platform and API ecosystem

 • Contributing to production readiness including reliability, observability, and performance

 • Partnering with data scientists on prompts, model usage, and evaluation strategies