iOS Engineer - Design System

About the team: As an iOS Engineer on the Design System team, you'll translate SumUp's design language into a reusable, easy-to-use library of UI components and experience patterns — empowering product teams to build cohesive, accessible user experiences at scale. The Design System team works hand-in-hand with the Mobile Platform team to set standards and provide guidance across all product teams at SumUp. As we expand our ecosystem of merchant and consumer-facing products, this role offers a rare opportunity to shape the foundation that helps developers build faster and ship higher-quality experiences to millions of users worldwide. What you'll do: • Shape the core experience for both users and developers interacting with SumUp's iOS ecosystem • Collaborate closely with product and design teams to build components that are maintainable, consistent, and beautiful • Embed accessibility best practices into every component — from content descriptions and touch target sizing to color contrast and dynamic type • Provide hands-on technical guidance to product teams to deliver on company priorities, including the upcoming support for landscape orientation • Review code contributions, enforce design system conventions, and mentor engineers on best practices for reusable UI development • Lead the migration of legacy UIKit-based components to SwiftUI while maintaining system stability • Proactively identify and address technical debt to uphold a high bar for engineering excellence and codebase health You'll be a great fit for this role if you: • Bring 3+ years of professional iOS development experience, ideally on large-scale or consumer-facing applications • Are fluent in Swift, with deep hands-on knowledge of both SwiftUI and UIKit — and a clear view on when and how to use each • Bring experience building or contributing to a design system, component library, or shared UI framework, and understand what it takes to make components truly reusable and scalable • Take pride in crafting accessible user experiences — you know your way around VoiceOver, dynamic type, color contrast, and touch target standards, and treat accessibility as a first-class concern, not an afterthought • Bring a strong grasp of testing best practices for UI components, including unit tests, snapshot tests, and UI automation • Are comfortable reviewing code and mentoring peers — you enjoy sharing knowledge, giving constructive feedback, and raising the bar for the whole team • Are self-motivated and structured in your working style — you manage your own priorities, communicate clearly in English, and thrive in a cross-functional, collaborative environment • Stay genuinely curious about the iOS ecosystem — you follow Apple's releases closely, experiment with new APIs, and are excited to bring fresh ideas back to the team Why you should join SumUp: 🌎 Opportunity to work with SumUppers globally on large-scale fintech products used by millions of businesses worldwide, from our Berlin office. This involves an office-first setup 🌈 Commitment to Diversity and Inclusion: be part of a workplace that values and promotes diversity, fostering an inclusive environment where everyone's perspectives are respected and embraced 🚀 Enrolment onto our Virtual Stock Option programme: you will own a stake in SumUp's future success 📚 A dedicated annual L&D budget of €2000 for your individual development, which you can be used to attend conferences and/or advancing your career through further education 💶 A corporate pension scheme where we match up to 20% of your contributions 🏖️ Generous time off: enjoy 28 days of paid leave plus public holidays and special leave days 🚵🏾‍♂️ Numerous other benefits such as Urban Sports Club subsidy, Kita placement assistance,