Senior Software Engineer, Android - KMP

About the team

SumUp’s Point-of-Sale (POS) solution empowers cafes, shops, bars, hair salons, and other businesses to operate efficiently and grow. It offers a wide range of features, including product catalogs, inventory management, business analytics, compliance support, and loyalty tools.

Our POS solution integrates seamlessly into the SumUp SuperApp, which supports both our proprietary register hardware and mobile devices like tablets and phones.

As a Senior Android Developer, you’ll collaborate with a dynamic, cross-functional team of Product Managers, Product Designers, Engineering Managers, and fellow engineers.

About the role

We’re evolving toward a Kotlin Multiplatform (KMP) strategy, enabling shared development across Android and iOS. In this role, you’ll learn, refine, and help implement this technology, shaping the future of our mobile apps.

You’re a developer who values user-centric design, precision, and seamless collaboration. You bring structure to communication and thrive in a cross-functional environment. 

This role will be a B2B based role in Warsaw.

What you’ll do

• Build new features for the item catalog within the SumUp SuperApp
• Help improve the architecture of the application and contribute to our Kotlin Multiplatform strategy
• Enhance and maintain our unified android app, distributed across 60+ countries, ensuring high-quality, scalable solutions
• Shape the product’s evolution by identifying opportunities for improvement and contributing to daily decision-making
• Write thorough documentation and implement robust testing for features before shipping
• Collaborate closely with Designer, Product Manager and Android engineers to deliver a unified UX experience across platforms

You’ll thrive in this role if:

• You have 8+ years experience in mobile engineering with Android and Kotlin.
• You have 2+ years of experience working with Jetpack Compose.
• You have a solid understanding of software design patterns (e.g., MVVM, MVI) and expertise in building modular, scalable app architectures.
• You have good knowledge of reactive programming (Flow, Coroutines and Concurrency).
• You have a strong grasp of testing best practices: knowing what to test, why, and how to write resilient tests.
• You strive for clean code, and you are flexible to balance pragmatism and perfection.
• You have a keen interest in multi-platform development using Kotlin Multiplatform.

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