Senior Software Engineer (Team Contract)

Build the technology behind our holiday contracts At Sunweb Group, we are developing a new internal application for creating and managing contracts with our suppliers and contractors. As our Senior Software Engineer, you will help build this application from the ground up and replace an existing legacy solution with a modern, future-ready platform. You will have the opportunity to shape both the technical foundation and the way the new team works. This is a new team with an initial size of approximately two to three engineers. You will first be onboarded within Team Dalyan, working in a group of around five colleagues. Once the new Contracting Team is established, it will separate into its own team with a dedicated scope and responsibilities. Location: Rotterdam Sunweb Group office (Hybrid) Start date: December 2026 Availability : Fulltime What you’ll do • Design and build a new application for creating and maintaining supplier contracts. • Develop cloud-native solutions using C#, .NET and Microsoft Azure. • Build user-friendly React applications for internal users. • Help replace a legacy application with a scalable and maintainable modern solution. • Contribute to system design, architecture and data-modelling decisions. • Develop reliable integrations and work with SQL-based data. • Apply automated testing, CI/CD and DevOps practices throughout the development lifecycle. • Communicate technical decisions, progress, risks and dependencies clearly. • Take ownership from…