Senior Fullstack Engineer - Partnership & Enterprise

As the Partnership and Enterprise squad's Senior Full-Stack Engineer, you'll take end-to-end ownership of the Partner Portal, the product that sits at the heart of how SumUp's partners manage their merchants, fees, and operations. You'll shape technical direction, collaborate closely with CRM engineers and product stakeholders, and ship features that directly reduce operational friction for the teams driving SumUp's sales growth.

What you'll do

• Build and own the Partner Portal's frontend using React, TypeScript, and Next.js, creating fast, reliable, and well-structured user-facing experiences
• Design, build, and maintain the services and microservices that power the portal, ensuring reliability and high availability at scale
• Write and maintain back-end APIs, services, and data pipelines in TypeScript and Go that are scalable and built to support a fast-growing global platform
• Develop fee management functionality and other high-impact features that directly reduce the administrative burden on partner management teams
• Implement monitoring and alerting, and follow up on incidents to keep the platform stable and performant
• Collaborate with colleagues and stakeholders across the Partnerships team to identify areas of improvement, collect feature requests, and shape solutions
• Actively contribute to code reviews, team ceremonies, and chapter rituals, sharing context and knowledge across engineering disciplines to avoid silos

What you'll need

• Proven experience with TypeScript and React, building scalable, production-grade full stack applications using frameworks such as Next.js, Remix, Nuxt, or similar
• Solid experience designing and working with RESTful APIs and complex microservice systems, with comfort navigating and refactoring large codebases
• Solid knowledge of Go, or strong experience with another backend language such as Node.js, used to build reliable, performant backend services
• Experience as a Kubernetes user, with familiarity in CI/CD pipelines and infrastructure tooling such as Terraform
• Comfort working closely with CRM systems or adjacent tooling (e.g. Salesforce), and an openness to bridging the gap between CRM engineering and full stack development
• A product mindset, connecting technical decisions to real business outcomes, and a genuine sense of ownership over the features you build from planning through to maintenance

What they offer

• Work with SumUppers globally on large-scale fintech products from the Berlin office
• 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, Urban Sports Club subsidy, Kita placement assistance, and subsidised office lunches