Python Developer

trg.; Greater London; Remote; GBP 72,000 - 88,000; Full time

Benefits offered by this job

Health insurance

Pension

Mostly remote UK

Education reimbursement

Wellbeing perks

Company performance bonus

Job summary

trg. is building a brand-new AI platform and hiring engineers to own the backend.

You’ll design, build and own Python backend services—from media upload through ML processing to delivering insights—and craft clean REST APIs for internal and external use. You’ll work with Claude Code daily, contribute to MCP servers, and push code to production with strong reliability and observability in a fast-paced product team.

Qualifications

• 3–6 years of commercial software engineering with strong backend Python (Django, FastAPI, Flask)
• Experience designing and building REST APIs used by others
• Shipped and owned code on a live SaaS product
• Hands-on experience with a major cloud (AWS ideal)
• Solid database and data modelling skills
• Familiarity with Claude Code daily and building skills/subagents
• Experience building MCP servers or strong understanding of MCP
• Product engineering background in cross-functional teams
• Ability to frame ambiguous problems and act quickly

Responsibilities

• Designing, building and owning Python backend services across the stack
• Designing clean REST APIs for headless frontends and integrations
• Building MCP servers for AI agents and tools
• Working with Claude Code to accelerate team delivery
• Taking code to production with testing, observability and reliability
• Contributing to infra as code on AWS as platform moves from Azure
• Collaborating with data scientists to productionise ML models
• Prototyping early ideas to test concepts before team commits

Skills

Backend Python

REST APIs design

AWS cloud

Database modelling

Claude Code

MCP servers

Product team collaboration

Ownership & pace

Tools

Azure

Terraform

Celery

Job description

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.