Staff Software Engineer - C# / .NET At a glance Staff-level engineering role on a high-scale, mission-critical payments platform Drive architecture, technical strategy, and engineering standards Hybrid working with Belfast city centre office Salary up to £75k About the Company Our client is a Fintech technology organisation operating at significant scale, enabling seamless commerce across international markets. Their platforms process millions of transactions daily and are engineered for high availability, security, and performance. With a well-established and growing engineering hub in Northern Ireland, they continue to invest heavily in modernising and scaling systems that underpin critical payment flows across multiple regions. The Role This is a Staff-level engineering position within a high-performing Belfast team responsible for a large-scale, high-throughput payments platform. You will operate as a technical leader and hands-on engineer, contributing to complex system design while shaping long-term architectural decisions. You'll work closely with senior stakeholders, mentor engineers across the team, and play a key role in driving engineering excellence across the platform. This role suits someone who enjoys balancing deep technical problem-solving with strategic influence. Key Responsibilities Lead the design and development of complex, scalable, high-throughput systems Influence architectural decisions and contribute to long-term technical strategy Drive best practices across code quality, testing, and maintainability Provide technical leadership and mentorship to engineers across the team Collaborate with cross-functional teams to deliver features from roadmap to production Identify performance, scalability, and reliability improvements across the platform Support production systems, troubleshoot complex issues, and drive root cause analysis Contribute to CI/CD pipelines and continuous delivery practices Promote a culture of engineering excellence, ownership, and continuous improvement What You'll Need 7+ years' commercial software engineering experience Strong background in backend development using C# / .NET Proven experience designing and building scalable, distributed systems Strong experience with RESTful APIs and web services Solid knowledge of relational databases (SQL Server or similar) Strong understanding of object-oriented design, design patterns, and system architecture Experience influencing technical direction or mentoring engineers Excellent problem-solving and communication skills Experience working in Agile environments Eligibility: Must be based in Northern Ireland or within commuting distance of Belfast, with the right to work in the UK. Why Apply? Competitive salary up to £75k plus bonus Hybrid working with a Belfast city centre office 26 days annual leave plus bank holidays Private medical and dental cover High-trust environment with real ownership and autonomy Opportunity to shape architecture on a mission-critical platform Strong focus on engineering excellence and career progression For more information, connect with Neill Ferguson on LinkedIn or submit your CV via the link below. Skills: c# .net sql fintech backend hybrid belfast Benefits: Work From Home