About The TeamSumUp'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 RoleWe'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 is on-site in Cologne, where face-to-face interactions spark innovation and teamwork.What You'll DoBuild new features for the item catalog within the SumUp SuperAppHelp improve the architecture of the applicationEnhance and maintain our unified android app, distributed across 60+ countries, ensuring high-quality, scalable solutionsShape the product's evolution by identifying opportunities for improvement and contributing to daily decision-makingWrite thorough documentation and implement robust testing for features before shippingCollaborate closely with Designer, Product Manager and Android engineers to deliver a unified UX experience across platformsCoach and mentor other engineersYou'll thrive in this role if:You have 5+ years experience in mobile engineering with Android/KotlinYou 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 SumUpThe opportunity to work on large scale fintech products used by millions of small businesses around the worldA dedicated annual Learning & Development budget for attending conferences and/or advancing your career through further educationEnrollment onto our virtual stock ownership program - you will own a stake in SumUp's future successA corporate pension scheme28 days' paid leaveYou'll attend global offsites and/or hackathons.You'd enjoy other great benefits such as Urban Sports Club subsidy, Kita placement assistance, subsidized office lunches and other location-tailored benefits, Babbel language platform subscription and moreJob Application TipWe recognise that candidates feel they need to meet 100% of the job criteria in order to apply for a job. Please note that this is only a guide. If you don't tick every box, it's ok too because it means you have room to learn and develop your career at SumUp.