Senior Software Engineer (Android) - Service Agreement

Rate: 135 – 170 PLN/hour (B2B) We are looking for an experienced Senior Software Engineer to join Flix on a freelance/service agreement basis (a 1-year B2B contract). This is a contractor engagement for a seasoned professional who doesn’t just write code but thinks about the entire mobile ecosystem, including performance, quality, scalability, UX, and testing. Scope of Services Bring expertise in building high-quality, scalable, and user-friendly Android applications to enhance the Flix passenger journey — optimizing key features such as post-booking and home page experiences, while incorporating innovative solutions that drive mobile development excellence. About the Engagement • Design, develop, and maintain high-quality Android applications with a focus on scalability, performance, and user experience. • Support closely iOS, Backend, and feature teams to align on feature specifications and ensure seamless cross-platform integration. • Drive technical improvements across the entire codebase, including architecture enhancements and codebase modernization. • Enhance app performance and user experience through UI optimizations, accessibility compliance, and improvements in battery usage, memory management, and load times. • Leverage analytics & metrics to make data-driven decisions, optimizing performance and engagement based on user behavior and app health. • Write clean, maintainable, high quality and testable code, ensuring high test coverage through unit, integration, and UI tests to guarantee reliability. • Actively contribute to improving CI/CD pipelines, app stability, and release processes, driving faster delivery and higher productivity. • Maintain clear, up-to-date technical documentation, including API specs, architectural decisions, and code comments, fostering transparency and knowledge sharing within the stakeholders. About You • 6+ years of Android development experience with a proven track record of building high-quality, user-facing Android apps. • Strong expertise in Kotlin (Jetpack Compose, MVVM, Coroutines), with a deep understanding of Android architecture and best practices. • Hands-on experience with performance optimizations, background services, memory management, and smooth user interactions (UI, animations). • Experience with testing (unit, integration, UI testing) and a strong commitment to writing testable, maintainable code. • Ability to drive technical strategy, ensuring high standards in code quality, performance, and scalability. • Understanding of SOLID principles and software architecture patterns. • Experience working with CI/CD pipelines and automated deployment systems (GitLab, Fastlane, Docker). • Experience with Firebase SDK, including Firebase Analytics, Remote Config, and Crashlytics. • Customer-centric approach with a focus on delivering great user experiences. Cooperation model • Cooperation based on a service agreement (B2B/freelance contract), not an employment contract. • You will operate as an independent contractor, responsible for delivering agreed services and submitting invoices • Location: open for contractors based in Poland