Senior Android Engineer (m/f/d) at unzer

ABOUT US     Unzer is a leading European fintech company with a mission to simplify international payments for e-commerce and retail businesses. Our brand was formed from 13 companies that now contribute to building a unique product covering the entire payment flow.     At Unzer, we are driven by the belief that customers should enjoy a seamless shopping experience, no matter where they choose to shop. We are a team of over 750 experts from 70 different nationalities, dedicated to creating a state-of-the-art unified commerce platform. Our goal is to enable businesses to delight their customers with a seamless payment experience.     Whether you're a tech enthusiast, payment expert, or a dedicated support professional, we are looking for individuals who are passionate about making a difference.     Our offices: We are based across Austria, Denmark, Germany and Luxembourg with a HQ in Berlin.   ABOUT THE TEAM    As a member of the Android Engineering team, you will play a pivotal role in building and evolving Unzer's in-store product suite — including POS Go (our all-in-one cloud point-of-sale for retail and gastronomy), OrderPro (wireless restaurant ordering on Android), and Livehub (customer-facing display). You'll work across dedicated payment hardware (PAX, CCV, Verifone), integrate with card terminals via ZVT/OPI protocols, and ship software used daily by thousands of merchants across Germany and Austria. This is a small, autonomous team where your decisions have direct product impact. What your work will look like: • Build and ship Android applications for real-world restaurant environments, delivering software directly to dedicated hardware like Pax A920 and A960 devices. • Own features end-to-end — from architecture decisions through implementation to production rollout. • Maintain and evolve a mature, production-grade Kotlin codebase used by thousands of active merchants. • Drive modernization efforts, including migration to Jetpack Compose, adoption of Kotlin Multiplatform (KMP), and implementation of clean, modular architecture. • Integrate with hardware components such as payment terminals, receipt printers, and barcode scanners, solving complex real-world challenges. Work on offline-first systems, including local persistence with Room and synchronization strategies. • Leverage AI tools like Claude for agentic coding, architectural exploration, and code reviews as part of the daily development workflow. • Collaborate within a small, high-impact team to deliver scalable, reliable, and maintainable solutions. • Contribute to CI/CD processes using GitHub Actions and maintain high code quality with tools like Detekt and ktlint. • Ensure application stability and performance using Firebase tools such as Crashlytics, Analytics, and App Distribution. What You Need To Be Successful In This Role: • 5+ years of professional Android development experience with strong expertise in Kotlin. • Solid understanding of software architecture patterns such as Clean Architecture, MVVM, and modularization, including their real-world trade-offs. • Hands-on experience with Jetpack Compose or proven experience leading or contributing to UI framework migrations. • Familiarity with or strong interest in Kotlin Multiplatform (KMP) for shared business logic across platforms. • Experience working with hardware integrations or embedded Android systems (e.g., printers, payment terminals, device-specific behaviors). • Strong knowledge of offline-first architectures, including sync mechanisms and local databases like Room. • Experience with modern Android development tools and frameworks such as Coroutines, Flow, Retrofit, OkHttp, Hilt/Dagger, and Navigation Component. • Comfort using AI development tools (e.g., Claude, Copilot) effectively as part of the engineering workflow. • Ownership mindset with the ability to work proactively in a small team without relying on fully defined tasks. • Nice to have: experience with POS systems, payment integrations (e.g., OPI, terminal SDKs), Compose Multiplatform, Ktor, Coil, or contributions to open source. Please note that we will not sponsor your visa or relocation, and you must have a valid work permit to be eligible for this position. What’s next? • Does it sound exciting? - Apply with your CV in English. Please don’t shy away if you don’t meet all the requirements! We’re looking forward to meeting you. • The interview process includes: a 30min intro call with a TA Partner, technical call with your potential manager 60-90min, 30-min leadership interview, 30 minute onsite conversation . Please note the process might alter depending on our team’s availability. WHAT’S IN THERE FOR YOU:     🏡 Work from home up to 60% of the time. We want you to keep your work-life balance.  🚲 Mobility support, whether you choose Swapfiets, Jobrad, or a Deutschlandticket - we've got you covered.  🫴 Explore counseling assistance, be it for professional or personal matters, through our associated platform.  💰 Pension scheme, we want to give back and help you secure your future.  🏖️ 15 days a year of workation from your desired destination within the EU.  🕟 Flexible working hours – helping you balance work and life 📗 Learning budget of 1000 euros per year – you can develop your passions with us.  🎉 Enjoy some fun moments with your coworkers – we throw a company party once a year and host several team events!    *Unzer is an equal employment opportunities workplace, and we commit to hiring regardless of race, sex, gender identification, sexual orientation, national origin, native language, religion, age, disability, marital status, citizenship, genetic information, pregnancy, or any other characteristic protected by law. Please refrain from including your picture and age with the application.     #LI-HYBRID