Senior Full Stack Python Engineer

The Opportunity The purpose of this role as Senior Full Stack Engineer is to design and ship end-to-end features across our AI governance platform — from a scalable Python backend on AWS through to the TypeScript/React front-end that gives users clarity and control. This is a hands-on, high-impact individual-contributor role at the centre of a fast-moving start-up: you’ll own features from concept to production, make pragmatic architectural decisions, and translate complex, governance-led product thinking into a platform that is scalable, secure and trustworthy for the business customers who rely on it. You will report to the Director of Technology and work in close, day-to-day collaboration with the Lead Developer, the UI/UX Lead and the wider engineering team — pairing engineering and design closely together to underpin the rapid launch and development of our AI-native service. You’ll be joining early enough to shape not just the platform, but how engineering happens. The Role The Senior Full Stack Engineer role sits at the intersection of backend, front-end and AI-augmented delivery. You will take features from concept through to production, working across three areas: a scalable Python backend on AWS, harness-based AI-assisted development workflows, and a TypeScript/React front-end that gives users clarity and control over the platform. Key Responsibilities ● Design, build and ship full-stack features — a scalable, secure Python backend on AWS and a polished TypeScript/React front-end. ● Work hands-on with our cloud infrastructure (Terraform, Kubernetes, EKS) to deploy and operate the services you build. ● Use harness-based, AI-assisted development workflows — running Claude Code or similar coding agents in automated loops to handle the majority (80%+) of the SDLC, from planning through implementation, testing, and review. ● Partner closely with the UI/UX Lead to turn designs into responsive, accessible, high-quality interfaces. ● Uphold engineering standards: code quality, CI/CD, testing, and release practices. ● Contribute to technical direction and roadmap discussions with the Director of Technology and founders. ● Use AI tools throughout your own workflow — for planning, coding, testing and review — to accelerate delivery without compromising quality. ● Continuously look for better ways of working — in your process, your tools and your output Profile ● 5+ years’ experience of shipping production software end-to-end as a senior engineer. ● Strong Python backend development experience in scalable (5+ years), production systems, including distributed systems, asynchronous architectures and APIs. ● Strong TypeScript (2+ years) and modern front-end development experience (React). ● Solid hands-on AWS experience (5+ years), with working knowledge of Terraform, Kubernetes and EKS. ● Hands-on experience developing software using Claude Code or similar AI coding agents, running them in automated loops and using them to drive 80%+ of the SDLC (planning, coding, testing, review). ● Professional experience with LLM-based systems or AI/ML product development. ● Comfortable owning full-stack architecture decisions for the features you deliver. ● Comfort operating in an early-stage, fast-changing environment, where priorities shift and ambiguity is normal — someone who leans into that rather than waiting for certainty. ● Excellent collaboration skills, working as an equal partner to both product and design. ● Master’s degree in a STEM field (Computer Science, Software Engineering, or related discipline). ● Nice to have: experience in governance, compliance, security, or regulated industries. ● Nice to have: prior experience at an early-stage startup, ideally pre-Series A. The Problem You’ll Help Solve Technology is evolving rapidly, and organisations need new tools to understand and manage its impact. In this role, you will help address challenges such as: ● ensuring complex technologies remain transparent and accountable ● helping organisations adopt AI safely and responsibly ● building governance systems that support innovation rather than slow it down. You will work alongside talented colleagues and forward-thinking partners to create solutions that shape the future of responsible technology. What You’ll Help Build The initial build of all new product capabilities: ● designing and building the scalable backend and infrastructure underpinning corporate memory and governance frameworks for advanced technologies ● building and continuously improving technology platforms ● working with partners to co-create new tools and capabilities ● translating complex technical or regulatory concepts into practical, shippable engineering solutions ● contributing to the evolution of products, research, or partnerships. What Success Looks Like Success in this role will be defined not just by tasks completed, but by the impact created. Examples may include: ● Well-crafted, end-to-end features shipped to production with measurable customer adoption ● A reliable, scalable full-stack codebase that supports rapid product iteration ● High standards of quality and security carried across both backend and front-end ● Clear linkage between the features you ship and commercial growth We look for people who take ownership of outcomes and continuously seek better ways of working. Location: London, UK (Hybrid — 3 days/week in office) Team: within the Engineering organisation Salary: £85,000 to £110,000 p.a. Reports to: Director of Technology Works closely with: UI/UX Lead, Product Director, and the wider Product and Engineering team building an AI-native product from the ground up. Please provide your current residential location when applying. Please note. 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