Full Stack Engineer – Python / FastAPI / React

Full Stack Engineer – Python / FastAPI / ReactContract | UK Remote | Up to £575 per dayWe are seeking an experienced Full Stack Engineer to support a client operating within a heavily regulated environment.This is a hands-on development role for an engineer who enjoys writing code, building features and delivering high-quality software. You will work within an established client engineering environment, following its development standards, security requirements, change controls and review processes.The role is predominantly remote, with very limited onsite requirements at the client's London location. Applicants must be based in the UK.Contract DetailsDay rate: Up to £575 per day Outside IR35 depending on experienceStart date: ASAP – immediate availability or short notice preferredDuration: Initial contract through to March/April 2027Location: UK-based, predominantly remoteOnsite expectations: Very limited attendance at the London officeIR35: Determination pending; current working assumption is Outside IR35Essential Skills and ExperienceCandidates should have strong hands-on experience across the following:Python: Strong commercial Python development experience.FastAPI: API design, middleware and asynchronous programming patterns.Pydantic: Data validation and API modelling.Database engineering: PostgreSQL data modelling, query design and migrations, using Alembic or a comparable schema-migration tool.Frontend: React and TypeScript, with the ability to support smaller feature updates.Authentication and authorisation: Experience with SSO, JWT and role-based access control.Testing: Automated testing using pytest and a JavaScript testing framework.Git and GitHub: Branching strategies, pull requests, code reviews and working within mandatory CI checks.AI-assisted development: Practical, day-to-day experience using Claude Code or a comparable agentic coding tool. Hands-on Claude Code experience is essential.Code quality and security: Ability to critically review AI-generated code, identify issues and ensure secure coding practices, including secrets management, protecting sensitive information and resolving security scan findings.Enterprise delivery: Comfortable working asynchronously within a client-owned repository, following established coding conventions, formal change controls, ticketing systems and structured review processes.Experience delivering AI-powered solutions is also important.Desirable ExperienceThe following would be advantageous:PingFederate.Rules-engine or workflow-engine design, including configurable rules, conditional logic and versioned templates.Concurrency and data-integrity patterns, including locking, idempotency and audit logging.Azure services, particularly App Service, Key Vault, managed identity and Application Insights.Advanced Claude Code capabilities, including custom skills, subagents, parallel worktrees and agent configuration.GitHub Copilot for code review.WCAG 2.1 AA accessibility standards and enterprise design systems.Vite and the npm toolchain.Experience working on regulated client engagements, particularly within sectors such as pharmaceuticals.The Ideal CandidateYou will be an experienced application or software engineer with a strong coding background and a track record of delivering within regulated or enterprise environments.You should be comfortable taking ownership of development tasks, building and improving application features, working with modern AI coding tools and ensuring that generated code meets the required standards for quality, security and maintainability.This is not primarily a platform or infrastructure engineering position. The client is looking for engineers who are actively involved in software development and can contribute to delivery from day one.Availability: Candidates who are immediately available or able to start at very short notice are particularly encouraged to apply.To be considered, please submit your latest CV outlining your relevant Python, FastAPI, React, Claude Code and regulated-environment experience.