Senior iOS Engineer
SumUp
London, England, United Kingdom · Onsite · Full Time
Posted
Job description
About the Role At SumUp, we're on a mission to bring merchants and consumers closer together and help local communities thrive. With SumUp Consumer , we're building a rewarding banking experience that connects people to the small businesses they love while enabling free transactions for our merchants. SumUp Consumer helps consumers manage their money with ease and get more from everyday spending. It offers seamless payment experiences and financial tools designed for modern life—spanning banking, cards, savings, and open banking. This is a high-impact, hands-on engineering role where you'll own the development and quality of the SumUp Consumer iOS application . You'll work directly on the features that consumers interact with every day, collaborating closely with Backend Engineers, Product Managers, Designers, and Android Engineers to deliver polished, reliable, and impactful mobile experiences. What you'll do Build and ship features across key consumer banking product areas—including KYC flows, card management, savings, open banking consent, and payment experiences. Write clean, testable Swift code and participate actively in code reviews to uphold high engineering standards across the codebase. Contribute to and evolve the iOS app architecture , including modularisation, dependency management, and scalability patterns as the product grows. Own performance and reliability by monitoring crash rates, proactively identifying issues, and driving app stability before they impact consumers. Maintain a culture of quality by writing unit and UI tests and contributing to the health of our CI/CD pipelines. Collaborate cross-functionally with Backend Engineers on API design, Product Managers on roadmap priorities, and Designers on seamless user experiences. What makes you great for this position Strong proficiency in Swift and deep knowledge of the iOS framework (Objective-C knowledge is a plus). Solid understanding of RESTful API integration and experience working with backend engineers on API design. Experience working with agile methodologies , CI/CD pipelines, and pair programming. Deep care for user interaction, usability, and interface quality—you build things that feel great to use. Ability to understand a large problem, design a solution, break it into deliverable chunks, and ship it independently. Passion for clean, maintainable, and testable code and a genu…