Full Stack Senior .NET Developer

We are looking for a senior .NET developer with a strong backend focus and solid frontend knowledge, who enjoys working both on existing (legacy) applications and on the modernization towards future‑proof solutions.

You will play a key role in maintaining, modernizing and building business‑critical systems, while gradually taking ownership within the team and contributing to the overall technical direction.

The role combines working on existing applications, modernizing legacy systems and building new solutions based on evolving business needs, with the opportunity to take end‑to‑end ownership and grow towards a more senior or leading role over time.

Your responsibilities

• Design, develop and maintain backend‑driven web and API solutions using .NET Core, C#, ASP.NET (Web API / MVC).

• Maintain and modernize existing legacy applications (WPF / WinForms) and contribute to migration strategies towards more modern architectures.

• Translate functional needs into technical solutions and work independently on complex challenges.

• Build and consume REST APIs and ensure secure integration between systems.

• Contribute to frontend development using React and/or Blazor, in collaboration with designers and other developers.

• Ensure code quality through testing, reviews and documentation.

• Act as a senior reference point in the team and mentor less experienced developers.

• Think along about technical direction, architecture and future evolutions.

Your profile

• 7–10 years of experience as a developer in a .NET environment.

• Strong experience with .NET Core, C#, ASP.NET, Entity Framework.

• Experience with React and/or Blazor.

• Familiarity with legacy Microsoft technologies (WPF / WinForms) or a strong willingness to learn and work with them.

• Experience with REST APIs and application security concepts.

• Experience with CI/CD and Git; knowledge of containerization (Docker, OpenShift, Kubernetes) is a plus.

• Interest in cloud technologies (Azure is a plus).

• Interest in modern development approaches (e.g. AI-assisted or agentic development) is a strong plus.

• Strong problem-solving skills, autonomous working style and a strong sense of ownership.

• Ability to take end-to-end responsibility and interest in growing towards a more senior or leading role over time.

• Ability to reflect on complex problems and know when to seek alignment.

• Fluent in English; Dutch is a plus.

Our offer

• A comprehensive mobility program that supports work-life balance.

• Continuous learning and professional development opportunities.

• A dynamic, innovative environment with real opportunities for growth.

• A people-centric culture with a strong focus on wellbeing and health initiatives.