Staff Software Engineer

Staff Software Engineer - C# / .NET Ocho People | Technology Recruitment Staff-level engineering role on a high-scale, high-throughput payments platform Lead architecture, technical strategy and engineering standards across the team Hybrid working - Belfast city centre office with flexibility to work remotely Salary up to £75,000 Fortune 500 fintech processing billions of transactions across 175+ countries About the Company You will be working for a leading payment technology and software organisation operating at significant global scale, enabling seamless commerce for businesses across more than 175 countries. Their platforms process billions of transactions daily and are engineered for exceptional availability, security, and performance. A Fortune 500 company and member of the S&P 500, they're a recognised leader in their space and continue to invest heavily in engineering innovation. Their Belfast team is a key part of that story. The Role This is a Staff-level engineering position within a high-performing Belfast team responsible for the Merchantware and Semi-integrated payments platform, a mission-critical system handling millions of card transactions daily for clients ranging from small businesses to 70,000-seat NFL stadiums. You'll operate as a technical leader and hands-on engineer, contributing to complex system design while shaping the long-term architectural direction of the platform. Throughput and resilience are at the heart of everything this team does, and you'll play a central role in maintaining their 100% uptime standard. This role offers genuine autonomy, real ownership and the chance to mentor engineers across the team. Key Responsibilities Lead the design and development of complex, scalable, high-throughput systems across the payments platform Drive best practices across code quality, testing, documentation and maintainability Provide technical leadership and mentorship to software engineers of varying levels Own architectural decisions and contribute to long-term technical strategy Perform and advise on testing, validation and corrective measures for complex code deficiencies Apply in-depth knowledge of PCI security compliance standards across software development lifecycle Provide accurate estimates on complex initiatives, projects and technical issues Collaborate cross-functionally with business and technology teams to deliver client-facing solutions Identify problems, integrate information from multiple sources and communicate solutions clearly Assist with software deployment to internal test environments and production data centre What You'll Need 6+ years' commercial software engineering experience Strong background in server-side development using C# / .NET in a Windows environment Experience designing and implementing scalable web service solutions Solid understanding of relational databases (SQL Server or similar) Experience working in CI/CD environments (e.g. Bamboo, Jenkins, GitLab) Familiarity with test automation - Unit tests, BDD / SpecFlow Knowledge of design patterns, OO design principles, refactoring and software architecture Experience in Agile / Scrum or Lean / Kanban delivery environments Must be based in Northern Ireland or within commuting distance of Belfast, and eligible to work in the UK on a permanent, full-time basis Why Apply? Salary up to £75,000 Hybrid working - choose between a modern Belfast city centre office and remote working 26 days annual leave plus bank holidays, increasing with length of service Comprehensive insurance package - medical, dental, life, critical illness and income protection 5-8% matching pension contributions with salary sacrifice option 26 weeks company-paid maternity leave Stock purchase plan, cycle to work scheme and electric car scheme High-trust environment with genuine ownership, autonomy and technical impact Real opportunity to shape architecture on a mission-critical, globally significant platform How to Apply For more information or a confidential conversation about this role, connect with our team on LinkedIn or submit your CV via the link below or email