Ryosuke Shimizu

Mobile Tech Lead / Cross-Platform Software Engineer

Tokyo, Japan

GitHub · SpeakerDeck · Avvy · AnotherBall Tech Blog

Last updated: September 2026

Professional Summary

Software engineer with 8+ years of professional experience, with deep expertise in Android/Kotlin and hands-on experience across Kotlin Multiplatform, iOS integration, real-time media, backend APIs, and cross-platform product development.

Currently working as Android Tech Lead / Mobile Engineer at AnotherBall, building Avvy, a global avatar-based live-streaming and social entertainment platform. I own the Android domain, lead technical decisions across mobile development, and contribute to shared cross-platform domain and SDK work with Kotlin Multiplatform.

My experience covers the full product-development lifecycle, including requirements alignment, UX and technical design, implementation, testing, release, production monitoring, KPI analysis, and operational improvement.

My strongest differentiator is working across the boundaries of mobile, real-time systems, native platform integrations, and emerging shared runtime components. Recent work includes Android/iOS shared tracking SDKs, on-device speech recognition integration, LLM streaming client modules, quality verification for a Rust-based avatar rendering core, and reliability/safety mechanisms for AI-powered product features.

I also have prior backend experience with Kotlin and Spring Boot, and I am intentionally expanding my scope toward backend, cloud, platform, and system architecture while maintaining mobile as a core strength.

I currently work in a bilingual Japanese and English environment. Source code, pull requests, and code reviews are written in English, while meetings, product discussions, specifications, and day-to-day communication use both Japanese and English.

Selected Highlights

• Lead the Android domain for Avvy while contributing to Kotlin Multiplatform shared layers and cross-platform SDK work spanning Android and iOS.
• Work across mobile, real-time, tracking, and shared-runtime boundaries, including MediaPipe/ARKit-based tracking, on-device ASR integration, LLM streaming clients, and quality verification for a Rust-based avatar core.
• Spoke at DroidKaigi 2026 on practical techniques for overcoming MediaPipe Face Landmarker accuracy limits and designing KMP APIs around platform capability differences, and at iOSDC Japan 2026 Rookies LT on cross-platform differences in facial-expression tracking.
• Led a gift-combo feature from competitive research and UX design through architecture, implementation, release, and KPI analysis, achieving sustained adoption and materially increasing daily gift volume.
• Contribute to reliability and safety mechanisms for AI-powered product features, including guard registries, budget/snapshot consistency checks, kill-switch-oriented design, and session lifecycle safeguards.