Senior DevOps Backend Engineer .NET

Senior DevOps Backend Engineer .NET | Build the new employer portal for millions of pension members | Major Dutch pension provider

A major Dutch pension provider is rebuilding the portal that thousands of employers use every month to file their pension declarations. The new platform is built in .NET, React/TypeScript and Azure, and it serves millions of members. The team is looking for a hands‑on Senior .NET engineer. You will help shape the new build while also keeping the current portal stable.

About the role

You will join an Agile DevOps team, mainly building backend functionality for the new Employer Portal. You will also maintain the existing ASP.NET application on .NET Framework 4.8, which employers still use daily. The role is 36 to 40 hours per week with a chance of extension. You will be based in Heerlen with only one fixed office day (Tuesday), so the rest of the week is flexible.

You will:

• Build new backend functionality, REST APIs and system integrations in .NET on Azure
• Review and contribute to frontend work in React and TypeScript
• Maintain the existing ASP.NET (.NET Framework 4.8) portal, including bug fixes and technical improvements
• Resolve production incidents and take part in Agile DevOps ceremonies

About you

• Senior-level experience in C# and modern .NET backend development
• Hands‑on experience with ASP.NET on .NET Framework
• Experience building REST APIs and integrations, ideally on Azure
• Comfortable reviewing or contributing to React/TypeScript code
• Able to work from Heerlen every Tuesday