Senior Frontend Engineer – Sell Online

In this role you will own frontend features for merchant-facing products like Payment Links and Gift Cards, and contribute to integration products and SDKs used across SumUp. You’ll collaborate in a cross-functional, agile environment to ship new features, reduce tech debt, and improve performance, accessibility, and observability. This is a hands-on, impact-driven position with ownership from day one, shaping product evolution for a global merchant base.

• office in Cologne, open and multicultural team
• Virtual Stock Option programme
• annual L&D budget of 2000
• 28 days paid leave + holidays
• commute subsidies
• Urban Sports Club access mostly covered by SumUp pedestrians? (fitness) — Urban Sports Club benefits clarified in text) - include: Urban Sports Club access with company cover?

• Build and maintain frontend features for payment links, gift cards, and online checkout
• Contribute to integration products and SDKs used by internal teams and external partners
• Participate in technical planning, design reviews, and sprint ceremonies
• Reduce tech debt and improve performance, observability, and accessibility
• Monitor live services and respond to issues, providing redundancy for customer support requests

• 5+ years of experience with TypeScript and JavaScript
• Hands-on experience building production-grade React and Next.js apps (including SSR and app router)
• Experience with unit, integration, and end-to-end testing (Jest, Vitest, or React Testing Library)
• Comfort with CI/CD workflows and agile environments (Scrum or Kanban)
• Experience with UI libraries such as Radix or shadcn and strong UX/accessibility understanding
• Product mindset with autonomous, end-to-end feature delivery

• product mindset
• autonomy
• collaboration in cross-functional teams
• TypeScript
• JavaScript
• React