Senior React Developer - Web/Mobile

**Senior React Developer \- Web/Mobile** **\*About Us\*** At Kaspper, we take technology seriously – but without losing the fun! 😎 We are a people\-driven company creating tailor\-made solutions that bring peace of mind to our clients. We work on challenging and innovative projects for leading companies in Brazil and abroad such as Santander, Bayer, Honda, Safra, PwC, Whirlpool, and many more. 🌎✨ 👉 Learn more: www.kaspper.com **Role description:** We are seeking a passionate React Developer who is dedicated to creating high\-performance, scalable, and visually engaging web and mobile applications. You will collaborate closely with product managers, designers, and backend engineers to deliver seamless experiences across both web and mobile platforms. **Key Responsibilities** Design and develop web applications using React.js and mobile applications using React Native. Optimize and maintain codebases for performance and reliability. Integrate RESTful APIs, gRPC, GraphQL, Firebase, and various third\-party libraries. Build reliable solutions for offline capabilities and local data persistence. Enforce best practices in coding standards, testing, and performance optimization. Collaborate closely with UI/UX teams to translate design mockups into polished, responsive, and user\-friendly interfaces. Stay current with the latest trends and developments in the React ecosystem and mobile development. **Required Technical Skills** **Fluency in English is mandatory, both written and spoken, for effective collaboration across global teams.** **3\+ years of professional experience in web and mobile app development.** **3\+ years of hands\-on experience with React.js and React Native.** Strong understanding of React architecture, including state management (Redux, Context API), components, and hooks. Deep knowledge of web and mobile app performance optimization, memory management, and debugging techniques. Familiarity with native Android development (Kotlin/Java) or native iOS development (Swift/Objective\-C) is a plus. Experience with Firebase for analytics tracking, crash reporting, and app distribution. Comprehensive understanding of App Store and Play Store deployment processes. Experience with CI/CD pipelines for web and mobile applications. Good knowledge of version control systems, branching strategies, and collaborative development workflows. Solid understanding of security practices, including data encryption and secure storage. **Qualifications** Bachelor's degree in computer science, engineering, or equivalent experience. Strong analytical, problem\-solving, and debugging skills. Excellent communication skills and an ability to thrive in a collaborative environment. Self\-motivated and capable of working independently with minimal supervision, as well as within a team setting. **✨ If you are passionate about product strategy, prioritization, and making an impact, join us at Kaspper and help shape the future!**