Contact
HIRE MOBILE DEVELOPER
Senior mobile engineer with 8+ years shipping production Android and cross-platform apps at Rakuten and U.S. Bank. Available for fractional mobile lead roles, architecture audits, and full delivery — remote, worldwide.
Last updated: May 2026
START A CONVERSATIONWhy hire me
8+ years production experience
Shipped Android at Rakuten-scale e-commerce and U.S. Bank enterprise banking, plus cross-platform Flutter apps to App Store and Google Play. Deep expertise in native Kotlin, Flutter, MVVM, MVI, and multi-module architecture.
Native + cross-platform
I know exactly when native Kotlin delivers uncompromising performance and when Flutter or KMP cuts delivery time in half without sacrificing quality. Native modules for platform-specific capabilities; shared layers for business logic.
Remote-native collaboration
Structured daily standups, async updates via Slack/Linear, and weekly video check-ins when needed. Based in Japan, collaborating with teams across APAC, EU, and US.
Full-stack capability
Beyond mobile — Next.js web delivery, Firebase/Supabase backends, RevenueCat subscriptions, push notifications, and ASO/SEO growth strategy. One partner for your entire product stack.
What you get
- Fractional Android lead — architecture, code review, and sprint planning
- Native Android (Kotlin) with MVVM, Redux/MVI, Dagger/Hilt, and multi-module structure
- Cross-platform delivery with Flutter or Kotlin Multiplatform
- Production diagnostics — crash/ANR analysis, memory profiling, and device-specific fixes
- CI/CD setup (Bitrise, GitHub Actions) and release pipeline automation
How it works
Discovery
Stakeholder interviews to align on product vision, followed by a deep codebase audit covering architecture, test coverage, and build times. I then recommend platform selection — native Android, Flutter, or Kotlin Multiplatform — based on your timeline, existing team shape, performance requirements, and long-term maintenance capacity.
Architecture
Design of modular project structure, dependency injection strategy using Dagger or Hilt, state management patterns such as MVVM or MVI, and API contract design with strong typing. All major decisions are documented in an Architecture Decision Record to preserve context for future team members.
Development
Sprint-based delivery with structured PR templates, mandatory code review, and weekly demo sessions. Native modules are used for platform-specific capabilities like camera or Bluetooth, while shared UI and business logic layers eliminate duplication across iOS and Android.
QA & Release
Comprehensive automated testing including unit tests, integration tests, and screenshot testing to prevent visual regressions. CI/CD pipelines on Bitrise or GitHub Actions manage staging builds, staged rollouts, and automated crash monitoring integration for production confidence.
Growth
Post-launch ASO metadata optimization, store asset preparation including screenshots and preview videos, analytics instrumentation with Firebase or Amplitude, and a dedicated support window to stabilize crash rates and user retention metrics.
Recent delivery
Deckbase
Learn with decks, FSRS spaced repetition, rich templates, and AI-assisted card creation.
Case study →
LoA
Mindful app usage: pause before distracting apps with intention, gratitude, and affirmations.
Case study →
Engagement
Fractional Lead
2–3 days per week embedded with your team. Ideal for ongoing roadmap delivery, architecture decisions, and mentoring while you scale.
Project-Based Delivery
Fixed-scope sprints (4–8 weeks) with clear milestones. Best for MVPs, feature launches, and greenfield builds.
Advisory Retainer
Architecture review, code audits, and technical strategy on a monthly basis. Perfect for teams that need senior oversight without full-time commitment.
Trust
8+
Years experience
4+
Apps shipped
24h
Response time
1 week
Paid trial
Trusted at
Testimonials
Yosuke delivered our iOS and Android apps simultaneously with shared architecture. Both platforms felt native, and we launched 3 weeks ahead of schedule.
— CTO, Mobile-First Startup
Our mobile engagement increased 40% after Yosuke rebuilt our apps with modern architecture. The performance difference was immediately visible.
— VP Product, Social Platform