(Senior/Mid) Software Engineer, Golang - Payments Platform

SumUp enables businesses to get paid easily, process orders quickly, sell online instantly and manage their money more efficiently. We create the tools businesses need to make their business and their customer experience thrive. The payments processing platform, consisting of other sub-platforms, has powered SumUp’s global business for more than 10 years now. It’s developed in Sofia by the Payments Tribe, composed of several teams (squads). Each squad is cross-functional, autonomous and co-located, working on its part of the platform end-to-end. We are scaling and improving existing products, while developing new ones - an exciting time to join. You would make an impact by improving and co-creating our existing and new microservices architecture platforms, solving scaling and new development challenges. Scalability and high availability are among our focus areas. What you’ll do Design and evolve systems that process millions of transactions reliably and at scale Build and maintain backend services in a microservices architecture Contribute to API design for internal services and external integrations Write clean, maintainable, and scalable code with strong test coverage Participate in architectural discussions and drive technical decisions Collaborate closely with engineers, QA, and DevOps to deliver production-ready systems Continuously improve engineering practices, including leveraging AI to iterate faster You will be great for this role if you have: Strong programming experience in any modern language (e.g. Go, Java, Python, Kotlin, etc.). We care more about how you think and design systems than the specific language you use Solid understanding of system design, scalability, and distributed systems Experience building APIs and working with data storage systems Ability to learn new technologies quickly and pragmatically Strong problem-solving skills and a structured way of thinking Ownership mindset and collaborative approach to teamwork Inte