Senior Software Developer

We're looking for an experienced Senior Software Developer to join a highly technical engineering team developing systems that directly support trading strategies, automated trading, and quantitative research.

This opportunity suits a strong C#/.NET engineer who enjoys complex technical challenges, performance-critical development and influencing how software is designed and built. Working across greenfield projects and established platforms, you'll take ownership of significant development work and help shape architecture, technical direction, and engineering standards. You'll collaborate closely with quantitative researchers, traders, and experienced engineers, translating complex requirements into reliable, scalable software.
This is a full-time office based role in central London.

The Role:

• Design and develop high-performance applications using C# and modern .NET.
• Own complex projects from initial requirements and technical design through to production.
• Shape architecture and contribute to key technical decisions.
• Build scalable systems supporting trading, research and data-intensive applications.
• Develop and optimise relational database solutions using SQL Server, Oracle or similar technologies.
• Investigate performance bottlenecks and improve application and database efficiency.
• Apply multithreading, concurrency and asynchronous programming to demanding engineering problems.
• Strengthen software quality through code reviews, automated testing and continuous integration.
• Mentor other developers and help maintain high engineering standards.

Skills Required:

• At least five years' commercial software development experience, with strong expertise in C# and modern .NET.
• Excellent understanding of object-oriented programming, software design principles and architecture.
• Experience delivering production applications where performance, reliability and scalability are essential.
• Strong SQL skills and experience with relational databases.
• A thorough understanding of the full software development lifecycle.
• Strong analytical skills and a practical approach to solving complex problems.
• Clear communication skills and the ability to work effectively with technical and non-technical colleagues.
• A degree in Computer Science, Mathematics, Physics, Engineering, or a related technical discipline.

Desirable Experience:

• Low-latency, high-throughput, multithreaded or parallel systems.
• Network programming using TCP/IP or UDP.
• Distributed systems and service-oriented architectures.
• Performance profiling and optimisation.
• Windows development technologies, Git and modern development workflows.
• Financial markets, algorithmic trading or quantitative research.
• Working directly with quantitative analysts, researchers, traders or data scientists.

Why Apply?

This is an opportunity to take on technically demanding work with a direct connection to trading and research. You'll have meaningful ownership, influence over engineering decisions and the chance to build high-performance software alongside colleagues with deep technical and quantitative expertise.

If you're an experienced C#/.NET developer looking for technical depth and the opportunity to shape complex systems, we'd like to hear from you.

Spectrum IT Recruitment (South) Limited is acting as an Employment Agency in relation to this vacancy.