Python Developer

Backend Python Engineer – AI Platform 📍 Remote, UK (one day a month in the office) Up to £80,000 + bonus The company Our client has spent more than 25 years using behavioural science to predict whether the world's biggest brands' ads will work. They test ads by measuring how people emotionally respond, and their predictions are checked against real in-market results. They're now building a brand-new AI platform from the ground up, and they're growing an in-house product and engineering team to own it. This is an established business making a real shift: from slow enterprise releases to a fast, product-led, AI-native way of building software. The role You'll be one of the engineers building the backend of the new platform. You'll sit in a small product team with a Product Manager, a Product Designer and a Team Lead, and help decide what gets built, not just pick up tickets. You'll be:

• Designing, building and owning Python backend services, from media upload through async ML processing to delivering insights
• Designing clean, spec-driven REST APIs for headless frontends, internal teams and customer integrations
• Building MCP servers so AI agents and tools can plug into the company's data
• Engineering through Claude Code every day, and building and sharing the skills, subagents and workflows that make the whole team faster
• Taking code into production with the testing, observability and reliability that enterprise clients expect
• Contributing to infrastructure as code on AWS, as the platform moves off its older Azure setup
• Working with data scientists to get ML models into production, and picking up the ML side as you go
• Building quick prototypes early to test ideas before the team commits to them What they're looking for
• Around 3–6 years of commercial software engineering, with strong backend Python (any framework: Django, FastAPI, Flask)
• Experience designing and building REST APIs that other people rely on
• Code you've shipped and owned on a live SaaS product
• Hands-on experience with a major cloud (AWS ideal)
• Solid database and data modelling skills
• You already use Claude Code daily and have built your own skills or subagents, and you can explain why you own every line you ship
• Experience building MCP servers, or a strong understanding of MCP and a real drive to build with it
• A product engineering background: you've worked in cross-functional product teams, not just large enterprise ones
• Ownership and pace: you're comfortable framing an ambiguous problem with your team and getting on with it Nice to have
• Infrastructure as code (Terraform or similar)
• Async or queue-based processing (Celery, SQS, Kafka)
• Exposure to ML systems or MLOps
• Enterprise security and compliance experience
• Some .NET or C# experience, useful for working around legacy services
• An interest in advertising and what makes it work What's on offer
• Up to £80,000 base
• Company performance bonus
• Health insurance and pension
• Mostly remote across the UK, with one day a month together in the office
• Education reimbursement and wellbeing perks
• A greenfield platform and real influence over the product What to include when you apply The team cares much more about what you've built and owned than about a list of technologies. Tell them about something you shipped, why it mattered, and how you use AI in the way you engineer.