Senior Backend Engineer - Golang

About the team

You’ll join the Sell Online Tribe, the group shaping how merchants bring their businesses to life online. We design and build tools that help millions of entrepreneurs, from barbers to bakers, sell their products and services anywhere. Our focus is on Online Store and Bookings, two products at the heart of SumUp’s ecosystem. Together, they give merchants the power to manage appointments, showcase their offerings, and get paid—all from their phones.

We’re a cross-functional team of Product Managers, Designers, and Engineers who move fast, collaborate openly, and care deeply about crafting beautiful mobile experiences. As part of this team, you’ll help us expand into new verticals, close the gap between web and mobile, and make digital selling effortless for small businesses everywhere.

About the role

You will be working on some of SumUp's biggest merchant-facing online products as part of the Bifrost team. You'll contribute to growing and scaling critical products like Payment Links, Virtual Terminal, and Unified Gift Cards, while also working on integration products that provide essential features used across many other SumUp products.

You're a developer who values reliability, collaboration, and continuous improvement. You bring backend expertise and thrive in a high-impact environment where your work directly supports merchant success and team scalability.

What you'll do

Provide redundancy for the scalability and continuous growth of some of the high-pri online products in SumUp

Contribute to the implementation, growth and integration of Online Checkouts throughout SumUp

Actively participate in planning and reviewing sessions on quarter and sprint levels by providing constructive feedback and estimations

Monitor existing services and make necessary fixes to ensure platform reliability

Implement new features with maintainable and testable code

Optimize and improve application performance for scalability

Participate in code reviews to ke