Backend Engineer - Run & Grow

About the Run & Grow: Run & Grow is where SumUp builds the platforms and capabilities that help merchants discover, join, use, and continue growing with our products. The tribe brings together engineering, product, design, and revenue operations teams around two connected goals: helping SumUp serve and retain merchants, and accelerating acquisition, activation, and engagement. Our work sits at the heart of SumUp’s growth engine. We turn complex challenges across merchant acquisition, identity, marketing technology, commercial systems, operations, risk, and compliance into reliable products and services that other teams can build on. The systems we create help SumUp move faster, make better decisions, and deliver a simpler experience to millions of small businesses. Joining Run & Grow means working on high-impact engineering problems with a broad view of the business. You’ll collaborate across disciplines and teams, shape the foundations behind important merchant journeys, and help create a more connected, scalable way for SumUp to run and grow. What you’ll do: Design, build, and operate production-grade backend services, APIs, and integrations, primarily using Go. Build event-driven workflows and distributed systems using technologies such as Kafka and asynchronous processing. Define clear service boundaries, data models, schemas, and API contracts that other teams can use confidently. Build capabilities supporting merchant acquisition, identity, marketing technology, operations, risk, and compliance. Own technical work end to end, from discovery and system design through implementation, testing, deployment, and production follow-up. Modernise existing services and improve reliability through observability, security, failure handling, and incident response. Collaborate with Product, Data, Operations, Compliance, Risk, Sales, Marketing, and other engineering teams to turn complex requirements into practical solutions. Review code and designs, make pragmatic technical trade-offs, share knowledge, and mentor engineers around you You’ll be great for this role if you: Bring a strong backend engineering background in Go, or are a typed-language generalist ready to ramp up quickly Have designed APIs and distributed systems with clear contracts, versioning, and integration patterns Are fluent in relational and analytical databases (PostgreSQL, Snowflake) and comfortable making the right choice for the right use case Have built Kafka-based, event-driven systems and understand event sourcing and CDC patterns Have experience in auditable, high-trust systems where every decision must be traceable fintech, payments, or similar domains Have experience with testing, observability, and incident response practices and treat them as first-class concerns, not afterthoughts Take ownership of ambiguous problems and turn them into clear, scalable, and maintainable solutions. Communicate clearly, collaborate effectively, and explain technical concepts and trade-offs to different audiences. Value pragmatic engineering, continuous improvement, mentoring, and reliable production operations. Why you should join SumUp: 🌍 Opportunity to work with SumUppers globally on large-scale fintech products used by millions of businesses worldwide, from our Sofia office. This involves an office-first setup 🧑‍🔬 We take learning and experimentation seriously with Hack Days every second Friday, and entire global Hack Weeks . 🌈 Commitment to Diversity and Inclusion: Be part of a workplace that values and promotes diversity, fostering an inclusive environment where everyone's perspectives are respected and embraced 📚 A dedicated annual L&D budget of €2,000 for attending conferences and/or advancing your career through further education 🚀 Enrolment onto our VSOP program: You will own a stake in SumUp’s future success 🏖️ Generous time off: 25 days of paid leave, plus one extra day per yea