Location: Berlin, Germany. Senior Fullstack Engineer – Identity at SumUp As a Senior Fullstack Engineer in the Identity team, you will be working on providing best‑in‑class authentication experiences and account protection for millions of users globally, as well as central services that enable teams and products across SumUp. We’re looking for someone who is adaptable, proactive, and ready to take ownership. Your primary focus will be on frontend development in TypeScript using React / Next.js, while forming the bridge to our backend development in Go. As part of a team with a broad scope, you’ll group with other engineers around and contribute to changing initiatives. Within those initiatives, you will get the chance to take ownership and drive topics end‑to‑end, from the collection of requirements and designing the solution, to orchestrating the rollout and communication with stakeholders. What you’ll do Take ownership of frontend development within the team, while helping to design and build clean and reliable APIs on the backend that serve the frontends. Closely align with our Product Designers and Mobile Engineers, creating a tight feedback loop. Employ and contribute to our internal Design System for a coherent experience across platforms. Create secure, user‑friendly self‑service features that empower our users to manage their accounts and contact preferences with confidence. Work with a talented distributed team that values collaboration, learning, and continuous improvement. Enjoy your work! We are looking for someone to be paid to do what they love. You’ll be great for this role if you have Professional frontend development experience with Typescript and React. Prior experience with full‑stack frameworks like Next.js would be helpful. Backend development experience, preferably with Go, focussed on API development. Excitement for security and reliability topics. Experience with authentication and authorization technologies (e.g. OAuth, Multi‑Factor Authentication) would be nice to have. A flexible mindset and the ability to adapt quickly in a fast‑moving environment and navigate complex domains. A structured, proactive way of working. You enjoy working independently but also effectively collaborate with your cross‑functional team and other teams. A natural drive to improve things—you're always looking to make systems and processes better. Confidence in asking for help or using available tools (like search engines or AI assistants) when something is beyond your grasp. Strong communication skills in English, both spoken and written. Why you should join SumUp Opportunity to work with SumUppers globally on large‑scale fintech products used by millions of businesses worldwide. We take learning and experimentation seriously with Hack Days every second Friday, and entire global Hack Weeks. Commitment to Diversity and Inclusion: Be part of a workplace that values and promotes diversity. A dedicated annual L&D budget of €2,000 for attending conferences and/or advancing your career through further education. VSOP program: Own a stake in SumUp’s future success. A corporate pension scheme where we match up to 20% of your contributions. 30‑day Sabbatical after completing 3 years of employment. Referral Bonus. Other benefits such as Urban Sports Club subsidy, Kita placement assistance, relocation assistance, subsidised office lunches. About us SumUp is on a mission to empower small businesses across the globe by providing simple and affordable tools that allow them to thrive. Our commitment to diversity and inclusion is reflected in our diverse team of over 3,000 SumUppers from over 90 nationalities. SumUp is an Equal Employment Opportunity employer that proudly pursues and hires a diverse workforce. SumUp does not make hiring or employment decisions on the basis of race, colour, religion or religious belief, ethnic or national origin, nationality, sex, gender, gender identity, sexual orientation, disability, age or any other basis protected by applicable laws or prohibited by Company policy. SumUp also strives for a healthy and safe workplace and strictly prohibits harassment of any kind. We recognise that candidates feel they need to meet 100% of the job criteria in order to apply. If you don’t tick every box, it’s ok because it means you have room to learn and develop your career at SumUp. #J-18808-Ljbffr