Senior React Native Developer

*Role: React Native Developer* *Location: Alameda, CA (3–4 days/week onsite)* *Job Description:* * Build and maintain consumer mobile features across iOS and Android using React Native, including CGM data visualization, AI-powered food logging, personalized metabolic insights, and AI health assistant experiences. * Own your areas of the React Native codebase end to end, from architecture and design through implementation, testing, and ongoing maintenance. * Write clean, well-tested, performant React Native code that works reliably across a wide range of iOS and Android devices and OS versions. * Identify and resolve performance issues across the React Native layer, including JavaScript thread bottlenecks, render * optimization, and memory management. * Work with native modules and understand how React Native bridges to iOS and Android platform capabilities, including integrations with CGM hardware SDKs and Bluetooth data streams. * Participate in Lingo's ongoing migration from React Native toward native iOS and Android where appropriate, contributing your perspective on what should migrate and how. * Conduct code reviews that raise the quality bar across the mobile team, sharing knowledge and holding a high standard for readability, testability, and maintainability. * Partner with Product and Design to translate requirements into well-scoped, high-quality engineering solutions and push back constructively when scope or approach creates unnecessary complexity. * Contribute to mobile testing practices, including unit, integration, and end-to-end testing across the React Native layer. *Required Qualification:* * Bachelor’s degree in computer science, Engineering, or a related technical discipline. * 5+ years of professional software engineering experience, with at least 3 years using React Native as a primary technology in a production consumer application. * Strong, demonstrable React Native expertise, including component architecture, state management, navigation, performance optimization, and the React Native new architecture (JSI, Fabric, Turbo Modules). * Working knowledge of iOS and/or Android platform fundamentals, sufficient to understand how React Native interacts with the native layer, read and interpret native code when debugging, and make informed decisions about native module usage. * Experience working with native modules in a React Native application, including consuming existing native modules and understanding how they bridge to platform capabilities. * Solid understanding of mobile application architecture patterns, including state management solutions (Redux, Zustand, or equivalent), navigation libraries, and offline-first design. * Experience with mobile performance profiling and optimization at the React Native layer, including identifying and resolving JavaScript thread and render performance issues. * Experience writing automated tests for React Native applications, including unit and integration tests and familiarity with end-to-end testing frameworks. *Preferred Qualifications:* * Hands-on experience writing native iOS code in Swift or native Android code in Kotlin, beyond reading and debugging into actively building native modules or platform-specific features. * Experience in consumer health, digital health, or regulated industries where software quality has direct implications for end users. * Familiarity with CGM, biosensor, or IoT data integration in mobile applications, particularly real-time data streams from wearable hardware. * Exposure to Bluetooth Low Energy protocols and mobile SDK integration for wearable or connected health devices. * Exposure to on-device AI or ML capabilities such as Core ML or TensorFlow Lite integrated within a React Native * application. * Experience with app store release processes for iOS and Android, including CI/CD pipeline integration for mobile builds. * Prior experience at a high-growth consumer technology company or digital health environment. Pay: $70.00 per hour Work Location: In person