Senior Full Stack Engineer (Greenfield Project)

Senior Full Stack Engineer | C# .NET | React | Greenfield Product | Belfast HybridAt-a-Glance

• Greenfield build.
• Backend-leaning full stack: C#, ASP.NET, Entity Framework and React
• Salary £55,000- £65,000
• Hybrid: three days a week in a Belfast office
• Exclusive to Ocho People... you won't find this role advertised anywhere else

About the Company

Our client is a global leader in financial and commodities market infrastructure, connecting traders and institutions to liquidity and data in every major financial centre. With a heritage stretching back well over a century and thousands of people worldwide, they offer the stability and scale of an established market leader. Their engineering teams build the software that brokers rely on every day to trade more efficiently across some of the world's most dynamic markets.

The Role

You'll join a small, self-directed team building a new trade ledgering and reporting product... described by the Head of Engineering as a mini start-up inside a corporate. The product is still taking shape, so you'll have real influence over what gets built and how, with end-to-end ownership of features from idea to production. The team moves quickly, embraces AI-assisted coding and is learning as it grows, so curiosity matters as much as a perfect CV. It suits a backend-leaning full stack engineer with a strong C# foundation who wants autonomy, pace and a genuine route towards technical leadership.

Key Responsibilities

• Build new product features end to end, from design through to production
• Shape the architecture of a greenfield product as it evolves
• Develop robust back-end services and APIs using C#, ASP.NET and Entity Framework
• Deliver clean, usable front-end features in React and TypeScript
• Use AI-assisted coding tools to move faster and raise quality
• Work directly with product owners and analysts to turn ambiguous requirements into clear solutions
• Champion automated testing, CI/CD and good engineering practice
• Troubleshoot and resolve issues in production
• Mentor less experienced engineers as the team grows

What You'll NeedEssential:

• Solid commercial experience as a full stack or backend-leaning engineer
• Strong C#, .NET and ASP.NET skills, ideally with Entity Framework
• Good relational database experience with SQL Server or PostgreSQL
• Working React experience... you don't need to be a front-end specialist
• Experience building and integrating APIs (REST, GraphQL or WebSockets)
• Comfortable owning features end to end within an Agile, autonomous team
• A curious, problem-solving mindset and the confidence to learn new technologies quickly