Product Engineer building and operating mobile products with React Native, TypeScript, and Node.js.

I work across product experiments, mobile performance and observability, React Native and Android platform debugging, and backend systems.

• React Native product engineering at monymony
• Mobile performance, observability, and release quality
• Product experiments from implementation through measurement
• Native platform debugging and migration validation

• Helped ship retention and purchase experiments for SumOne, a couples app with 19M cumulative sign-ups and about 1.2M DAU as of January 2026.
• Co-founded MatchConnection and shipped React Native apps, Node.js services, an LLM Q&A web app, and a Chrome extension.
• Built and operated Honeypot, a pedometer rewards app, to 500+ DAU and US$180 in monthly ad revenue.

• KeyboardExtender enabled-state reproduction: minimal Expo and React Native case for a dynamic enabled prop issue.
• Firebase Admin Node PR #2934: proposed APNs contentChanged payload support.
• react-native-keyboard-controller issue #1056: reported and documented a dynamic rendering issue on iOS.

React Native Expo TypeScript React Node.js NestJS GraphQL Relay AWS Firebase Sentry

Seoul, South Korea | ckrt4815@gmail.com