Senior Android Engineer

About us Ruby Labs is a leading tech company that creates and operates innovative consumer products. We offer a diverse range of opportunities across the health, education, and entertainment industries. Our innovative teams are driving the future of consumer-led products, and we're always looking for passionate individuals to join us. Learn more about our story at: https://rubylabs.com/about-us/ About the role As a Senior Android Engineer, you will play a key role in developing and maintaining our mobile app, ensuring high performance, scalability, and a seamless user experience. You will collaborate closely with the product manager and fellow developers to bring new features to life and continuously optimize our app. Your expertise in Kotlin and Android development best practices will be instrumental in driving innovation and maintaining our position as a leader in the Play Store. Key Responsibilities Develop and maintain a high-quality Android application with a focus on performance, UI, and UX. Take ownership of development processes, ensuring clean, maintainable, and scalable code. Work with cross-functional teams to design, develop, and launch new features. Implement CI/CD pipelines and deployment best practices. Conduct code reviews and enforce coding standards. Profile and optimize app performance (memory, jank, startup, battery, APK/AAB size). Stay up to date with the latest Android development trends and integrate relevant advancements. Qualifications 5+ years of professional Android development experience. Experience with B2C mobile apps built on subscription business models . Expert proficiency in Kotlin (coroutines, Flow, sealed classes, generics, extension functions). Strong command of Google Play Billing Library v7+ and subscription lifecycle: purchase flows, entitlement management, Real-time Developer Notifications (RTDN), and server-side validation (with RevenueCat or a custom equivalent). Deep understanding of Jetpack Compose and the Android View system , including interoperability and Compose state management (remember, State, StateFlow collection). Strong grasp of modern Android architecture: MVVM/MVI, Clean Architecture, unidirectional data flow, and modularization (Gradle multi-module). Proficiency with Jetpack libraries (ViewModel, Navigation, Room, WorkManager, DataStore) and Dependency Injection (Hilt/Dagger). Experience with CI/CD (GitHub Actions, Bitrise, or Gitlab CI), Gitflow, and Play Console / internal-track distribution. Automated testing experience: JUnit, Espresso, Compose UI testing, Turbine, and MockK. Strong debugging and profiling skills with Android Studio Profiler, LeakCanary, and Baseline Profiles. Experience integrating AI-driven features and/or AI-assisted development workflows. Location Ruby Labs operates within the CET (Central European Time) zone. Applicants from any country are welcome to apply for the position as long as they are located within approximately ± 4 hours of CET. This ensures optimal col