Senior Backend Engineer

Global Bank tribe In the Global Bank tribe, we are building the infrastructure and core services needed to provide our merchants with a digital bank account that empowers them to be successful at doing what they love. Our goal is to become the most popular banking partner for small merchants globally by offering a high-quality banking experience tailored to their needs—effortless, simple, and affordable. Joining the Global Bank tribe means playing a key role in helping us build SumUp's digital bank. You’ll collaborate with a global, autonomous, cross-functional team that refines an aspect of our product from concept to execution. Work alongside colleagues from 32 nationalities across Cologne, Berlin, São Paulo, Sofia, London and Vilnius, united by a shared commitment to taking ownership, working with purpose, and helping small businesses thrive. As a Senior Backend Engineer, you will play a key role in helping us transition from a localized setup with regional banks to a unified Global Bank. A significant challenge will involve supporting the move to a fully distributed, event-driven architecture. Our tech stack includes Go, AWS, Kafka, PostgreSQL, and Kubernetes, supported by a strong observability toolchain with Prometheus, Grafana, and Honeycomb. We also actively use AI‑assisted development tools such as Cursor, GitHub Copilot, and others. SumUp’s engineering culture is built around ownership. We follow a “build it, run it, improve it” model, with strong observability and a focus on learning. Engineers have clear scope and autonomy, with decisions documented, reviewed, and made collaboratively. The Vilnius team is a core part of the Global Bank domain. We own production systems, shape technical direction, and work closely with colleagues across SumUp’s global offices on critical merchant banking capabilities. Join our Vilnius Team today (Vilnius office). What You’ll Do - Collaborate with a global team to design and build a unified global banking platform. This includes high-level APIs for multiple regions and local implementations, ensuring high availability and observability - Be part of the transformation team that is transforming monolithic services into decoupled, highly scalable, region-agnostic, unified global bank services - Design, implement, and iteratively develop highly available backend services, while continuously evaluating and implementing new methods to ensure the high reliability of transfer systems - Maintain and improve core services utilizing a modern, cloud-native technology stack (AWS, K8s), with microservices written in Golang, Kotlin and Java and Elixir. - Improve test coverage for existing services and drive the end-to-end delivery of changes, including testing, observability, and monitoring. - Shape and continuously improve our engineering culture by sharing ideas, refining best practices, exploring innovative solutions, and contributing to comprehensive documentation and tool selection. About SumUp At SumUp, we’re on a mission to empower small businesses around the world with simple, affordable tools to help them start, run, and grow. More than 4 million merchants across 37 markets trust us as their financial partner — and we’re just getting started. We’re a global team of 3,000+ people from over 90 nationalities, united by curiosity, collaboration, and care. Our core values and culture shape everything we do, fostering inclusion, learning, and belonging.