Senior Full-Stack Engineer - Super

About the role

The SuperApp squad owns parts the merchant experience across Web, Android, iOS and the flows that millions of small business owners use every day to run and grow their businesses. As our dedicated full stack web engineer within the squad, you'll own this space entirely, shaping technical direction, driving feature parity for SumUp's web experience.

What you'll do

• Own and develop core web dashboard features including the first-time user experience, home screen widgets, quick actions, tools section, and communications centre
• Build and maintain the backend services that power these flows, ensuring a seamless and consistent experience across web and mobile
• Work closely with iOS and Android engineers, product managers, and designers to shape cross-platform solutions and contribute to technical direction
• Lead the design and refinement of technical solutions — writing clear documentation, making architectural decisions, and communicating progress to stakeholders
• Be an active contributor to the web chapter and the broader engineering community at SumUp

What you'll need

• Strong, proven experience with React.js and TypeScript, building scalable, maintainable frontend applications in a production environment
• Comfortable working across the stack, with experience building backend services or REST APIs, Go is a plus, but Node.js or similar is equally welcome
• Ability to navigate and refactor complex codebases with a focus on clean, durable code and solid system design
• Experience working in cross-functional teams alongside product managers and designers, with a strong sense of ownership and comfort with ambiguity
• A product mindset, thinking about the merchant experience, not just the code, and connecting technical decisions to real business outcomes

What they offer

• Work with SumUppers globally on large-scale fintech products from the Berlin office
• Virtual Stock Option programme
• Annual L&D budget of €2,000
• Corporate pension scheme with up to 20% match
• 28 days paid leave plus public holidays and special leave days
• 1-month sabbatical after 3 years of service, plus Urban Sports Club subsidy, Kita placement assistance, and subsidised office lunches