Blogs

Senior Android Engineer

Job Information:

Work Experience: 8+ Years
Industry: IT Services
Job Type: FULL TIME
Location: Tokyo, Japan

Role Overview:

We’re seeking a hands-on Senior Android Engineer to join our growing Mobile Platform team. You’ll own end-to-end architecture for large-scale Android applications—from defining backend APIs and data models through to client-side implementation, debugging, profiling and performance optimization. This role partners closely with Product, UX and Backend teams to deliver rock-solid, high-throughput mobile experiences used by millions of users.

Key Responsibilities:

  • Architect & implement complex, modular Android apps using Kotlin/Java and modern patterns (MVVM, Clean Architecture, Redux).
  • Define and collaborate on backend service contracts (REST) and data schemas to meet mobile requirements.
  • Lead the design of scalable, event-driven, microservices-oriented backends that integrate seamlessly with clients.
  • Own app performance: use Android Profiler, Systrace, LeakCanary, MAT and custom instrumentation to identify and fix CPU, memory, GPU and network bottlenecks.
  • Develop and enforce coding standards, code review processes and automated quality checks (Lint, SonarQube …).
  • Build and maintain CI/CD pipelines (GitHub Actions … ) for automated builds, tests and deployments.
  • Mentor and guide mid-level engineers on best practices for test-driven development (JUnit, Espresso, Mockito) and observability (Crashlytics, Firebase …).
  • Troubleshoot complex production issues, perform root-cause analysis and drive continuous improvement.
  • Collaborate across distributed teams, contribute to technical documentation, design reviews and architectural roadmaps.

Work Environment:

Our work environment is built on a foundation of collaboration and mutual support. We believe that the best ideas come from working together, sharing knowledge, and celebrating each other’s successes. We actively encourage professional development and provide opportunities for growth, empowering our employees to reach their full potential. We’re committed to creating a space where everyone feels valued, respected, and inspired to contribute their best work.

Minimum Qualifications:

  • 8+ years of professional Android development experience (Kotlin & Java).
  • Deep understanding of Android framework internals, application lifecycle, threading and memory management.
  • Proven track record delivering large-scale consumer or enterprise apps (100K+ daily active users).
  • Expertise in debugging and profiling tools: Android Studio Profiler, Systrace, Allocation Tracker, LeakCanary, MAT.
  • Strong background in RESTful/GraphQL API integration and offline data persistence (Room, SQLite, Realm).
  • Solid grasp of modern architecture patterns (Clean Architecture, MVVM, Redux) and dependency injection (Dagger/Hilt, Koin).
  • Experience designing or collaborating on backend services, message queues (Kafka, RabbitMQ), and cloud deployments (AWS, GCP, Azure).
  • Hands-on with building CI/CD pipelines and containerization (Docker).
  • Excellent communication skills, ability to influence technical direction and simplify complex problems.

Preferred Qualification:

  • Prior experience as a technical lead or architect in a fast-paced Agile/Scrum environment.
  • Familiarity with Kotlin Multiplatform, Jetpack Compose and cross-platform frameworks (Flutter, React Native).
  • Knowledge of mobile security best practices (OAuth2, JWT, certificate pinning, encryption).
  • Experience with A/B testing frameworks, feature flags (Firebase Remote Config).
  • Contributions to open-source Android libraries or technical blogs/presentations.