We are looking for an experienced VB.NET & C# Developer to join our team and work on modernising and maintaining desktop applications. If you have a passion for working with legacy code while implementing new features with WPF, WinForms, and MVVM, this role is for you! Your Profile as a C# Developer: Strong experience in backend development using VB.NET and C#. Expertise in desktop application development with WinForms and WPF. Ability to analyse and optimise complex data structures and improve system performance. Hands-on experience working with legacy code while ensuring maintainability and modernisation. Good understanding of MVVM, SQL databases, and jQuery. Proficiency in Visual Studio for efficient development and debugging. University degree in Computer Science, Software Engineering, or a related field. Fluent in both German and English. What to Expect: A dynamic work environment in a rapidly growing and innovative company. The chance to actively shape product development and modernise existing applications. Work in a motivated, agile, and technology-driven team that values collaboration. Hybrid work model – Enjoy a modern office in Cologne, with the flexibility to work remotely up to three days per week. Competitive salary, personalised training opportunities, and attractive corporate benefits.