English summary for screening — check the original posting before applying.
We are seeking a Senior Mobile App Engineer to lead the design, implementation, and quality improvement of our mobile applications. You will work within a fast-paced, AI-first development environment, leveraging Flutter and native technologies to redefine the e-commerce user experience.
Must-haves
- 3+ years of experience developing and operating commercial mobile apps with Flutter
- Deep knowledge of iOS or Android native development (3+ years)
- Experience leading performance optimization and crash reduction initiatives
- Experience with team development and code reviews using Git/GitHub
- Strong motivation to develop using AI-assisted tools like Claude Code and Cursor
Nice-to-haves
- Practical experience with both Swift and Kotlin
- Advanced Flutter plugin development and native integration via MethodChannel/FFI
- Implementing features using LLM APIs or on-device ML
- Experience with design systems and modular architecture
- Contribution to OSS, technical blogs, or conference presentations
Tech stack
FlutterDartSwiftKotlinFirebaseSentryGitHubGitHub ActionsFastlaneClaudeClaude CodeCursorDatadogAWSGCPVercel
Work style
Onsite in Tokyo. The team emphasizes in-person communication for team cohesion and spontaneous idea generation.
Other notes
Annual salary: ¥13,000,000 - ¥21,000,000.