Mobile App Engineer
Job Summary
You will be responsible for the development, operation, and enhancement of mobile applications for services like 'Sansan', 'Eight', or 'Bill One'. The role involves the full product lifecycle from requirements definition to implementation and performance optimization. You will collaborate closely with product managers and designers to improve user experience and architectural quality.
Responsibilities
- Develop and operate Android/iOS native applications
- Define requirements and propose new features
- Collaborate with designers on UI/UX improvements
- Perform feasibility studies and technical architecture design
Required Skills
- 3+ years experience in Android/iOS or Flutter
- Proficiency in Kotlin/Swift/Dart
- Mobile app architecture design
- Business-level Japanese fluency
Job Details
### Job Description
You will be involved in development that enhances product value, from requirements definition to implementation and operation of mobile applications.
- Development and operation of mobile applications (Android/iOS)
- Proposal of new features and improvement measures, and feasibility studies
- Specification and UI/UX discussions with product managers and designers
- Consideration of design improvements and introduction of new technologies to improve internal quality
### Development Environment and Tools
- **Languages:** Kotlin, Swift (partially Objective-C), Dart, TypeScript, Go
- **Frameworks and libraries:** Jetpack Compose, Retrofit / Dagger / Hilt, Kotlin Coroutines / RxJava, Alamofire / Realm / RxSwift, Flutter, Express.js, Ktor
- **Source code management:** GitHub
- **CI / Testing:** GitHub Actions, CircleCI, JUnit / XCTest, GitHub Actions for BFF
- **Operations and monitoring:** Firebase Crashlytics
- **Design and collaboration:** Figma, Slack / Teamflow
### Working Hours
- Flexible working hours
- Core time: 10:00-16:00
- Standard working hours per day: 8 hours
- Overtime: Average 20 hours/month
### Job Requirements
**Required Qualifications:**
- Experience in developing and operating Android/iOS native apps, or Flutter apps (3+ years)
- Experience in mobile app architecture design and library selection
- Knowledge of iOS/Android standard libraries and frameworks
**Preferred Qualifications:**
- Experience in developing and operating iOS/Android native apps with a large user base
- Experience developing with Kotlin Multiplatform
- Knowledge of UI design and implementation (Storyboard/Auto Layout, etc.)
- Experience with reactive programming
- Experience with development automation using CI environments and team code reviews
- Experience with agile development (Scrum)
- Experience leading development projects or team management
- Experience developing with generative AI/AI agents
- Experience in full-stack development
**Language Skills:**
- Business-level Japanese or higher required (JLPT N2 or equivalent)
- Business Conversation level English (TOEIC 735-860)