Android Developer (Construction Tech) w Kraków, Polska

Company Description Join a product-focused team developing modern mobile solutions used daily by hundreds of thousands of users across construction sites worldwide. We are looking for a Middle Android Developer who is passionate about scalable mobile applications, clean architecture, and modern Android technologies. We at Sigma Software collaborate closely with a sustainable European Customer headquartered in Sweden to build digital products that improve workforce management, operational efficiency, and worker safety. You will become part of a mature engineering environment with strong technical expertise and close integration into the Customer’s organization. This is an opportunity to work on long-term product development, contribute to business-critical solutions integrating software and hardware technologies, and grow alongside experienced Middle and Senior engineers. CUSTOMER Our Customer is a sustainable European product company headquartered in Sweden that develops digital solutions for workforce and construction site management. The company focuses on improving operational efficiency and worker safety through connected mobile applications and smart physical devices. Sigma Software engineers work as an integrated part of the Customer’s agile product organization. PROJECT The project focuses on building mobile and web products for workforce presence tracking and access management on construction sites worldwide. The platform combines software products with physical devices, allowing users to register entrances and exits, remotely unlock doors, and interact with construction machinery directly from mobile applications. The product is business-critical and continues to scale rapidly, serving hundreds of thousands of active users daily. The engineering team follows modern Android development practices with a strong focus on maintainability, scalability, and continuous improvement. Job Description Design, develop, and maintain Android applications using Kotlin and Jetpack Compose Participate in architecture discussions and technical decision-making Refactor, optimize, and modernize existing Android codebases Implement scalable and maintainable features following Clean Architecture principles Troubleshoot and resolve application issues and performance bottlenecks Integrate native Android capabilities including NFC, Bluetooth, and Camera SDKs Collaborate with cross-functional teams including iOS engineers, QA specialists, backend developers, and product stakeholders Participate in all phases of the software development lifecycle Contribute to code quality initiatives, peer reviews, and continuous improvement processes Support CI/CD and engineering automation initiatives Qualifications 3+ years of commercial experience in Android development Strong proficiency in Kotlin and modern Android development practices Hands-on experience with Jetpack Compose, Coroutines, Flow, Retrofit, and Android SDK Experience with MVVM and Clean Architecture approaches Solid understanding of software engineering fundamentals, including OOP, algorithms, data structures, and design patterns Experience with dependency injection and unit testing tools such as Mockito and JUnit Strong analytical and problem-solving skills Ability to independently drive feature development and technical solutions Strong communication and collaboration skills Intermediate or higher English level Bachelor’s degree in Computer Science, Computer Engineering, or equivalent practical experience WILL BE A PLUS Experience with Java, XML, and Android Data Binding Experience modernizing legacy Android applications Migration experience from XML-based UI to Jetpack Compose Experience transitioning legacy navigation approaches to Navigation Compose Experience with CI/CD pipelines and release automation Scripting and process automation experience Experience using AI-assisted engineering tools in development workflows Portfolio of published Android applications on Google Play or GitHub Additional information PERSONAL PROFILE Proactive and ownership-driven mindset Strong collaboration and communication skills Attention to code quality and maintainability Ability to work effectively in agile distributed teams Interest in modern mobile technologies and continuous improveme