Senior Backend Engineer - Cards

The Cards squad owns the systems that power card issuing, lifecycle management, and transaction processing for merchants across Europe. You'll take real ownership of complex, high-impact work in a high-throughput, distributed architecture handling millions of card transactions every day.

What you'll do

• Own and lead the end-to-end delivery of backend services within the Cards EU domain, including observability, testing, and production support
• Contribute to the technical roadmap by participating in architectural discussions and proposing solutions for complex, distributed systems challenges
• Raise well-scoped pull requests, conduct thorough code reviews, and help maintain high standards of code quality and test coverage across the team
• Collaborate closely with engineers in adjacent squads and with the product manager to shape and refine the squad backlog
• Participate in incident reviews and the on-call rotation, taking accountability for the reliability of the services you build
• Apply and champion AI tooling to accelerate engineering workflows, and help raise the team's overall AI literacy

What you'll need

• Solid, hands-on experience delivering production-ready backend services end-to-end, including testing, monitoring, and maintenance, on a modern cloud-native stack
• Production experience with Kotlin and interest in working with a number of other languages (Java, Golang and Elixir)
• Solid understanding of distributed systems, API design, data modelling, and working with relational databases
• Hands on experience in containerisation, orchestration, and CI/CD practices
• Ability to take an ambiguous product problem, define the technical approach, and lead it through to implementation with minimal guidance
• Comfort working across teams and communicating clearly in written and spoken English in a professional setting

What they offer

• Office-first setup in Berlin with opportunity to work globally on large-scale fintech products
• Virtual Stock Option programme to own a stake in SumUp's future success
• Annual L&D budget of €2000 for conferences and further education
• Corporate pension scheme matching up to 20% of contributions
• 28 days of paid leave plus public holidays and special leave days
• 1-month sabbatical after 3 years of service, plus additional benefits including Urban Sports Club subsidy and subsidised office lunches