Senior Full Stack Developer | C#.NET, React | London

Overview

As a Senior Full Stack Developer in London, you will build high‑performance digital products across backend and frontend, shaping architecture, delivery, and standards within Financial Services. You’ll drive secure, scalable solutions and contribute to CI/CD and cloud deployment. You work closely with product and design to deliver iteratively while mentoring peers. This is a hands‑on, impact‑focused role that values engineering craft and continuous improvement.

Responsibilities

• Design, develop, test, and maintain scalable services using C#/.NET (ASP.NET Core) and RESTful APIs
• Develop responsive UIs with React, TypeScript, HTML, and CSS
• Implement secure authentication/authorization (OAuth2/OIDC) and follow secure coding practices
• Improve performance, reliability, and observability (logging, metrics, tracing)
• Work with SQL Server and perform schema design, queries, and tuning
• Write automated tests (unit, integration, end-to-end) and participate in code reviews
• Collaborate with product, design, and stakeholders to refine requirements and deliver iteratively
• Contribute to CI/CD pipelines and cloud deployment practices
• Mentor engineers and promote best practices in engineering craft and delivery

Key requirements

• Extensive commercial experience with C#/.NET and React
• Strong knowledge of .NET Core, DI, asynchronous programming, and API design
• Strong React experience including state management and modern tooling
• Solid understanding of software design principles and clean code
• Experience with SQL databases, ORM tooling (Entity Framework), and data modeling
• Experience with cloud platforms (Azure and/or AWS), Docker, and CI/CD
• Understanding of Financial Services constraints: security, auditability, data protection, and resiliency
• Strong communication skills and ability to work effectively in an agile environment

• communication
• collaboration
• agile mindset
• C#/.NET
• ASP.NET Core
• RESTful APIs