Senior Full Stack Engineer

eFinancialCareers; Greater London; Hybrid; GBP 88,000 - 115,000; Part time

Benefits offered by this job

Hybrid working arrangement

Job summary

eFinancialCareers in London (Holborn) is seeking a Senior Full Stack Engineer for a hybrid contract role. You will build and enhance modern applications in a regulated environment, adhering to established engineering standards and delivery processes.

You will work hands-on across Python (FastAPI, Pydantic, PostgreSQL) and front-end (React/TypeScript), with a focus on secure coding, testing, and CI/CD. Remote: Holborn; hybrid working in Central London.

Qualifications

• Extensive Python development experience in modern web apps.
• Strong API design with FastAPI and async patterns.
• Proficient data modelling with Pydantic and PostgreSQL.
• Front-end skills in React + TypeScript; SPA delivery.
• Experience with authentication (JWT/SAML) and RBAC.
• Test automation with pytest and JS testing tools.

Responsibilities

• Hands-on development of modern applications in a regulated environment.
• Design, implement and optimize APIs and data models with security in mind.
• Review AI-generated code and manage CI/CD pipelines.
• Collaborate asynchronously within established engineering standards.

Skills

Python development

FastAPI

Async programming

Pydantic data modelling

PostgreSQL data modelling

React & TypeScript

Authentication & RBAC

Testing with pytest

Git & GitHub

CI pipelines

Claude Code usage

Code reviews

Security best practices

WCAG 2.1 AA accessibility

Vite & npm ecosystem

Tools

GitHub Copilot

Claude Code

Azure (App Service, Key Vault, Managed Identity, Application Insights)

Vite

npm ecosystem

Job description

£550 GBP

Hybrid WORKING

Location: Holborn, Central London, Greater London - United Kingdom Type: Contract

We're looking for an experienced Senior Full Stack Engineer to join a high-profile programme within a heavily regulated organisation. This is a hands‑on development role where you'll be building and enhancing modern applications while working within established engineering standards and delivery processes.

Rate: Outside IR35

Remote: Holborn

• Strong commercial experience with Python development.
• Excellent knowledge of FastAPI, including API design, middleware and asynchronous programming.
• Experience using Pydantic for data validation and API modelling.
• Experience with Alembic (or similar schema migration tools).
• Strong PostgreSQL skills, including data modelling, query optimisation and database migrations.
• Experience with React and TypeScript to support front‑end feature development.
• Good understanding of authentication and authorisation, including SSO, JWT and role-based access control (RBAC).
• Experience writing automated tests using pytest and JavaScript testing frameworks.
• Strong knowledge of Git and GitHub, including branching strategies, pull requests, code reviews and CI pipelines.
• Hands‑on experience using Claude Code (or a similar AI coding assistant) as part of your day‑to‑day development workflow.
• Ability to critically review AI‑generated code before submitting pull requests.
• Strong secure coding practices, including secrets management and resolving security vulnerabilities.
• Experience collaborating asynchronously within established engineering standards and code review processes.
• Desirable Experience PingFederate.
• Rules or workflow engine development.
• Concurrency, locking, idempotency and audit logging.
• Microsoft Azure, particularly App Service, Key Vault, Managed Identity and Application Insights.
• Advanced use of Claude Code, including custom skills, sub‑agents and agent configuration.
• Experience using GitHub Copilot for code reviews.
• Knowledge of WCAG 2.1 AA accessibility standards and enterprise design systems.
• Experience with Vite and the npm ecosystem.
• Previous experience delivering software within regulated enterprise environments such as pharmaceuticals, healthcare or financial services.