Senior iOS Engineer - Sell Online

About SumUp

Be empowered to do more that matters.

At SumUp, we're on a mission to empower small businesses across the globe by providing a vast set of simple and affordable business tools to help them start, run, and grow their businesses. Today, over 4 million businesses in 36 markets rely on SumUp as their financial partner to manage payments, finance and customer relationships.

About the Team

You’ll join the Sell Online Tribe, the group shaping how merchants bring their businesses to life online. We design and build tools that help millions of entrepreneurs, from barbers to bakers, sell their products and services anywhere. Our focus is on Online Store and Bookings, two products at the heart of SumUp’s ecosystem. Together, they give merchants the power to manage appointments, showcase their offerings, and get paid—all from their phones.

We’re a cross-functional team of Product Managers, Designers, and Engineers who move fast, collaborate openly, and care deeply about crafting beautiful mobile experiences. As part of this team, you’ll help us expand into new verticals, close the gap between web and mobile, and make digital selling effortless for small businesses everywhere.

What You’ll Do

• Implement new features with clean, maintainable, and testable code using Swift and SwiftUI
• Collaborate closely with designers and product managers to review and improve user flows
• Contribute to closing feature gaps and achieving parity between web and mobile
• Participate in code reviews and improve application performance and stability
• Support multiple squads as needed and contribute to shared technical foundations across Sell Online
  
  

You’ll Be Great for This Role If

• You have 5+ years of experience in iOS development
• You’re fluent in Swift and Objective-C, and comfortable building complex UI using SwiftUI and UIKit
• You understand Combine, MVVM-C and Dependency Injection, and have solid experience with RESTful APIs
• You’re experienced with CI/CD, GitHub Actions, and dependency management using CocoaPods and Swift Package Manager
• You write unit tests and know how to ensure quality through end-to-end testing
• You communicate clearly in English and thrive in a collaborative, cross-functional environment
• You care deeply about building products that empower small businesses and create real-world value

Why You Should Join SumUp (Warsaw) 🇵🇱

• 🌎 Opportunity to work , from our vibrant Warsaw office with inspiring art-filled lounges and a skyline terrace in the Mennica Legacy Tower. 
• 🌈 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 VSOP program: you will own a stake in SumUp’s future success 
• 🚴 Fitness support: work out on-site at our gym or explore the city using the Multisport Card, subsidised by SumUp for access to sports facilities across Warsaw 
• 🩺 Commitment to well-being: access health insurance coverage for you and your family, plus life insurance to further protect your peace of mind 
• 💰 PPK (Employee Capital Plan): grow your savings with joint contributions from SumUp and the State. 
• 🏖️ Generous time off: enjoy 26 days of paid leave plus public holidays and special leave days
• 🌴 Break4me: 1-month sabbatical after 3 years of service 
• 🔗 Referral Bonus: earn additional rewards by referring talented individuals to join the SumUp team