Senior Backend Engineer (Golang) - Balance Management

At SumUp, the Global Bank team builds the core infrastructure and services that give merchants a digital bank account, helping small businesses manage their money easily and reliably. The Balance Management Squad sits at the core of the Global Bank Platform. Right now, our team is completing a major milestone: consolidating and modernizing our balance management system in Europe. The next big step is creating a global transaction history service; a single, shared platform used by all regions to give merchants consistent and transparent views of their financial activity. As a (Senior) Backend Engineer , you’ll help modernize existing systems while balancing innovation with stability, collaborate with teams across regions, and build reliable services that manage diverse markets with different regulations. If you enjoy solving complex problems on high-load systems, are curious about banking, and are looking for a team that tackles challenges head-on, we’d love to hear from you. What You’ll Do Build and evolve the SumUp’s core banking services that powers ledger operations and transactions, transforming our regional systems into a unified, scalable global platform. Tackle complex distributed systems challenges, ensuring resilient services that continue to perform under high transaction volumes. Support modernization initiatives by improving observability, adding test coverage, refactoring code for long-term maintainability, and gradually introducing new architectural patterns without disrupting live banking operations. Contribute to key architectural decisions - build ledger and transaction history systems from the ground up, ensuring a globally scalable banking solution for our clients. Collaborate with teams across Risk, Treasury, Finance, and Infrastructure to ensure smooth, compliant, and reliable global operations Take ownership from design to production, running the services you build, monitoring their performance, and continuously improving how we deliver high-quality software at scale. You’ll be great for this role if You have solid backend experience building reliable, high-volume services and you think carefully about system design, APIs, data modeling, and how services interact. You are proficient in Golang and comfortable learning and working with other languages as needed, e.g. Kotlin or Elixir. You write maintainable, well-tested code, follow CI/CD best practices, and take responsibility for the software you build from development to production. You’re comfortable building, deploying, and running services in cloud environments like AWS using Docker and Kubernetes. You’re eager to learn about relational databases that perform well under load and maintain data consistency. You are a collaborator who enjoys working across regions, communicating clearly, exchanging feedback effectively, and making thoughtful technical decisions together. You have a curiosity for building reliable financial services and banking domain It’s a plus if you have Knowledge of Elixir - some of our legacy services are written in Elixir, and while it's not essential, it would be useful if you've worked with it before Deeper PostgreSQL experience - we rely heavily on Postgres, so if you've done performance tuning, complex queries, or schema design, that's a plus Experience with event streaming platforms (Kafka preferred) and modern observability stacks (Grafana, Honeycomb, etc.) Why you should join SumUp Be part of a company that values diversity and celebrates unique perspectives. Work with a global team of skilled professionals in an environment that fosters collaboration, learning, and growth. Be part of a global tribe building a banking solution from the ground up and delivering impactful solutions to the real-life problems of millions of SumUp merchants all over the world Career growth and learning opportunities: We invest in your development through regular training, mentorship programs, SumUp University leadership cohort and a yearly learni