C# React Full-Stack Developer

Senior .NET / React Developer – Global Markets

Inside IR35 Contract Role – London – Up to £850 per day

About the Role:

We are currently seeking an experienced Senior .NET Developer to join a leading global financial institution in London. This is a 6-month contract with strong likelihood of extension, working on critical desktop applications within their Global Markets technology team.

Key Responsibilities

• Enhance and maintain two business-critical desktop applications:
• A desktop application launcher/management system built with WPF and .NET
• A background business alerting application that processes system events
• Develop new React admin screens as part of extending these applications to new business units
• Participate in architecture improvements to support broader deployment
• Work closely with a small, collaborative development team

Technical Requirements

• Strong experience with .NET development and React
• Familiarity with event processing systems and messaging architectures
• Ability to work across both frontend and backend development

The Ideal Candidate Will Have

• Strong understanding of event-driven architectures
• Experience with asynchronous programming and multi-threading
• Exposure to financial services applications (though deep domain knowledge is not required)
• Ability to work independently in a small team environment

Work Environment

• Hybrid working arrangement: 50% office time (3 days one week, 2 days the next)
• Small, collaborative team of 3 developers based in London

Contract Details

• Day rate: Up to £850 per day
• Duration: 6 months initial term with expected extensions
• Location: London office

If you\’re an experienced .NET developer looking for a varied and technically challenging role within financial technology, we\’d love to hear from you.