Sungyu Kang

Frontend Platform Engineer

Viva Republica (Toss)

Dec 2024 - Present

React Native Framework Team

• Build React Native brownfield infrastructure for Toss, a Korean fintech app used by roughly 20 million people. App.js Conf team talk
• Chose React Native as the technical foundation and led the initial architecture for Apps In Toss, Toss's mini app business. Apps In Toss
• Designed brick-module, a JSI-based native module system conceptually similar to Nitro Modules, with a screen-scoped module registry for brownfield React Native apps. brick-module
• Built the independently bundled React Native runtime foundation for enterprise apps at Toss, including Apps In Toss, similar in shape to mobile microfrontend and super-app architectures. granite
• Built the Granite Screen brownfield integration layer so internal iOS ViewControllers and Android Activities can host independently bundled React Native screens. granite-screen
• Designed and implemented Granite Router, a React Navigation-based file-system type-safe router for independently bundled React Native runtimes. Granite Router guide

Software Developer

Brandazine (Inedit Corp.)

Jul 2022 - Nov 2024

• Led the gradual migration of a Cordova Vue 2 app to a greenfield React Native codebase.
• Designed the communication architecture between legacy WebView surfaces and React Native.
• Built end-to-end React Native app experiences while incrementally replacing Cordova-based flows.