Senior Software Engineer (Booking and Search domain)

At Sunweb Group, we're building and evolving the core systems behind millions of holidays each year. As a Senior Software Engineer in Team Capri, you'll own our Booking and Search domain , which is at the heart of how customers find and book their holidays. You contribute directly to how our platform is designed, scaled and improved. You'll work in a small, autonomous Agile team of four (two developers and two application engineers), where ownership, pragmatism and quality go hand in hand. This role goes beyond coding. You influence architecture, improve engineering practices and help the department grow. Location: Rotterdam Sunweb Group office (Hybrid) Start date: December 2026 Availability : Fulltime What you’ll do Help define the team's technical vision and architectural direction. Own the Booking and Search domain and improve usability and performance for both customers and internal users. Work hands-on with the team on backlog items and complex technical challenges. Review designs and facilitate important technical decisions. Guide the maintenance and improvement of critical external applications and supporting tools, including updates pushed by our software vendor. Improve monitoring and alerting to enable fast response, and find structural fixes or mitigations. Work towards decoupling our systems from external applications by implementing an anti-corruption layer and creating a stable domain that shields our internal systems. Collaborate with business users, other engineering teams and software vendors on changes, issues and dependencies. Translate product needs into practical technical solutions and help break down complex work. Improve engineering quality through code reviews, documentation, pairing and knowledge sharing. Mentor engineers and help them grow their technical skills and ownership. Communicate technical risks, trade-offs and dependencies clearly. Our tech stack C#, .NET, Azure, SQL, React, GitHub, GitHub Copilot, Visual Studio / VS Code We actively leverage AI-powered tools such as GitHub Copilot to improve productivity and code quality. What you bring 5+ years of experience with C# and .NET Experience building cloud-native applications on Azure Strong knowledge of SQL and data modelling Solid understanding of system design and clean architecture Experience with CI/CD, automated testing and DevOps practices Experience with legacy systems and modernisation Ability to balance speed and quality pragmatically Ownership mindset and drive to improve systems and processes Strong stakeholder communication skills in English (Dutch is a big plus) Experience mentoring others and shaping the technical vision and direction of a team Experience with Kubernetes is a big plus What we offer Yearly gross salary between 65K and 80K, excluding 8% holiday allowance). 25 holidays + 6 ATV days, based on fulltime employment. Please note: ATV days do not apply to part-time…