Backend Engineer - POS

SumUp's Point-of-Sale (POS) solution empowers cafes, shops, bars, hair salons, and other businesses to operate efficiently and grow. It offers a wide range of features, including product catalogs, inventory management, business analytics, compliance support, and loyalty tools. As a Backend Engineer in the Orders & Sales or Catalog Platform team, you will build the engine powering core infrastructure for over 4 million businesses worldwide. Whether you are architecting global sales APIs or scaling item management systems, your work is central to the SumUp ecosystem. The Orders & Sales team builds high-performance APIs and receipt engines that unify transaction and sales data, utilizing an AI-native mindset and extreme collaboration. Meanwhile, the Catalog Platform team owns the backend for item management, variants, categories, and taxes, focusing on high-stakes reliability and core POS infrastructure scaling. What you'll do • Develop and evolve high-performance backend services and APIs using Kotlin and Spring Boot. • Design and maintain robust data schemas and event-driven integrations (Kafka) to handle complex transaction and catalog data at scale. • Write clean, well-tested, production-grade code and contribute meaningfully to code reviews and team rituals. • Collaborate with mobile and product teams to ship end-to-end features with a focus on performance and data consistency. • Engage in daily pair programming to solve complex concurrency challenges and maintain high architectural standards. • Take full ownership of the development lifecycle, including managing CI/CD pipelines and monitoring service health in production. • Actively use and experiment with AI coding agents to automate repetitive tasks and increase shipping velocity. • Refactor and migrate mission-critical domain logic to centralize and simplify the "Sales" and "Catalog" experiences across the ecosystem. You'll be great for this role if • You have 3+ years of experience in backend eng