Project for international client from the heating, ventilation, and air conditioning (HVAC) technology industry. The project involves the development of a cross-platform mobile application (iOS + Android) using React Native for end users, which integrates with the company’s IoT devices.Location: Readiness to work in a hybrid work model (once a week at the client's office in Katowice).Our expectations Minimum 4 years of experience in React Native and 5+ years in general frontend development (JavaScript/TypeScript, HTML, CSS). Strong knowledge of React Native, including best practices for developing cross-platform mobile applications (iOS + Android). Experience in integrating mobile applications with IoT devices, including: reading device parameters (temperature, operating modes, energy consumption, historical data), controlling the device from within the app (schedules, on/off, operating mode settings), data synchronization with a cloud backend, handling push notifications. Ability to work with backends, microservices, and IoT platforms, including implementation of business logic and network communication. Experience with multi-brand and multi-language applications, scalable across different markets. Knowledge of mobile and integration testing, test automation, and CI/CD processes (e.g., Bitrise, GitHub Actions, Fastlane). Familiarity with tools for monitoring and debugging mobile applications. Ability to ensure application and communication security, including user authentication, data encryption, and protection of communication channels between the app, device, and cloud. Application performance optimization, including startup time, bundle size, responsiveness, offline mode handling, and connectivity issue management. Fluent English (B2). Welcome Skills Proficiency in TypeScript, Redux / MobX, React Navigation, and GraphQL. Experience working with highly scalable applications and integrating them with cloud platforms. Knowledge of UX/UI principles in the context of mobile applications. Experience in migrating existing applications to React Native or modernizing the technology stack. Understanding of mobile and IoT application security standards. Key tasks Design, development, and maintenance of mobile applications using React Native for iOS and Android platforms. Implementation of new features and optimization of existing solutions in terms of performance, security, and scalability. Integration of mobile applications with IoT devices. Participation in projects focused on developing multi-brand and multi-language applications for various markets. Creation and maintenance of unit and integration tests, as well as automation of deployment processes in a CI/CD environment. Monitoring, analysis, and debugging of application performance using appropriate tools. Ensuring a high level of application security – user authentication, data encryption, and protection of communication channels. Optimization of application performance regarding startup time, bundle size, responsiveness, offline mode support, and connectivity handling.