Senior Backend Engineer - Identity Lifecycle

<p><strong>About the team:</strong></p> <p>You’ll join one of the teams within SumUp’s Identity Lifecycle Mission, working on some of the most critical building blocks behind the merchant journey, from onboarding and identity verification to KYC/KYB, regulatory data collection, and managing customer identity throughout the entire lifecycle.</p> <p>Today, many of these capabilities live across different flows, legacy services, and tightly coupled integrations. We’re on a journey to bring these pieces together into a more coherent, scalable platform, with shared data models, reusable services, and clear ownership boundaries.</p> <p>As a Senior Backend Engineer, you won’t just be maintaining existing systems. You’ll have the opportunity to shape how our identity platform evolves, modernise critical services, and help build foundations that can support new regulations, markets, and product requirements without reinventing the wheel every time.</p> <p>You’ll be part of one dedicated team, but the challenges we tackle often cross team and domain boundaries. You’ll work closely with Engineers, Product, Design, Compliance, Risk, and Operations, giving you the opportunity to influence solutions well beyond your own team.</p> <p>If you enjoy solving complex backend problems, working in a highly collaborative environment, improving reliability, and building scalable capabilities that enable other teams to move faster, this could be an exciting opportunity to make a real impact at SumUp.</p> <p>&nbsp;</p> <p><strong>What you’ll do:</strong></p> <ul> <li>Design, build, and operate scalable backend services, APIs, event-driven workflows, and system integrations.</li> <li>Build reusable capabilities that power merchant onboarding, identity verification, and KYC/KYB regulatory data collection.</li> <li>Drive reliability and resilience across critical services through better observability, failure handling, incident response, and long-term risk reduction.</li> <li>Work primarily with Go, while maintaining and progressively modernising existing services written in Java.</li> <li>Evolve domain models and service boundaries while reducing legacy complexity, duplicated logic, and tightly coupled integrations, always with a pragmatic, incremental mindset.</li> <li>Own your work end-to-end, from technical design and implementation to rollout and production follow-up.</li> <li>Work across team and domain boundaries, turning ambiguous product and regulatory requirements into clear, scalable technical solutions.</li> <li>Review code and designs, mentor engineers, and help raise engineering standards across the mission.</li> </ul> <p>&nbsp;</p> <p><strong>You’ll be great for this role if you have:</strong></p