Senior Mobile Engineer (React Native & Hybrid)

About the role

We are building a music streaming app used by millions in Japan and expanding from native iOS/Android to cross‑platform solutions. As a Senior Mobile Engineer you will lead the adoption of React Native, design its integration with existing native code, and set technical standards for the hybrid app.

Key responsibilities

• Define and evolve the React Native architecture, including folder structures, build pipelines, and coding standards.
• Ship high‑quality, user‑facing features on both iOS and Android platforms.
• Collaborate with native iOS and Android engineers to create and maintain native bridges, exposing core capabilities such as the custom audio engine.
• Own feature delivery end‑to‑end, from UI design and API integration to release and post‑launch optimisation.
• Improve app performance by tuning startup time, memory usage, and frame rates.
• Evaluate and prototype emerging cross‑platform technologies as product needs evolve.

Required profile

• Strong production experience with React Native and TypeScript, including performance tuning and state‑management.
• Proficiency with native mobile development environments (Xcode, Android Studio), dependency managers (CocoaPods, Gradle) and troubleshooting build/link errors.
• Deep understanding of mobile fundamentals such as UI lifecycles, memory management and multithreading.
• Demonstrated ability to ship production‑grade mobile features and manage App Store / Google Play submissions, OTA updates and release workflows.

Required skills

• React Native
• TypeScript
• iOS development (Xcode)
• Android development (Android Studio)
• CocoaPods
• Gradle
• Swift (nice to have)
• Kotlin (nice to have)
• Claude Code or GitHub Copilot
• Flutter or Kotlin Multiplatform (nice to have)