Kubernetes, Akamai, Cloud CDN, Cloudflare, Terraform, Grafana, Prometheus, etc. Backend Go, MongoDB, AlloyDB, Bigtable, Firestore, Spanner, gRPC, Pub/Sub, BigQuery, etc. Web React.js, TypeScript, Jotai, React hooks, Tanstack Query, RxJS, Flux, Storybook, node.js, gRPC, Nginx, Fastly, webpack/Babel/PostCSS, etc. Android Kotlin, ExoPlayer, Jetpack Compose, Retrofit/OkHttp, Dagger Hilt, Gradle, Room, Clean Architecture, Kotlin Multiplatform, etc. iOS Swift, SwiftUI, Swift Concurrency, RxSwift/RxCocoa, Swift Package Manager, XcodeGen, SQLite, Realm, Clean Architecture, Kotlin Multiplatform, etc. Game Console C#, C++, Unity, UnityEngine, Nintendo SDK, PS4 SDK, Zenject, UniRx, R3