Backend Engineer (m/f/d) - Kotlin / Java

Ready to become part of the most important mission on this planet? We are rebuy, pioneers in the sustainable reuse of electronics and media, and we are looking for you! Our mission: to make circular living accessible to all, one transaction at a time. By giving products a second chance, we reduce resource consumption and avoid unnecessary e-waste. Our global team of 500 drives things forward collaboratively, takes personal responsibility, values constructive critical thinking, and is dedicated to serving our customers and planet. The Role We are looking for a passionate and experienced Software Engineer who loves working in a team and has a strong getting-things-done attitude. You will be part of a small but fun team of 4 people working on some of the most business-critical and technically interesting parts of rebuy's platform. Our scope covers AI-powered customer support automation, payment systems, and marketplace integrations (Amazon, eBay). We build on a modern, actively evolving stack, and we expect everyone on the team to use AI tools as a natural part of their workflow. Key Responsibilities: - Write code that is simple, readable, testable, and maintainable, whether you write it yourself or with the help of AI tools - Conduct code reviews, give helpful feedback, actively contribute in team discussions and decisions - Know the sweet spot between implementing beautiful and charming solutions which incorporate all existing software design patterns and just getting it done - Suggest changes to our software that simplify the technical architecture of individual services or pay down technical debt - Actively take over ownership for projects and collaborate with different teams across the organization - Maintain existing services and contribute to developing the new solutions