Work Portfolio
See the résumé for the full chronology.
Led React Native client development for a rewards app on a two-person team. Diagnosed unpaid rewards, moved receipt OCR preprocessing from the server to the client, and managed store and OTA releases.
Platform Modernization and Native Modules
- Led the React Native New Architecture (TurboModule/Fabric) migration and the RN 0.81 + Node 22 LTS upgrade, and designed a deploy-tracking tag convention while running 15+ store releases and 19+ OTA deployments.
- Designed and built three native libraries — on-device receipt OCR (ML Kit, VisionKit + Vision), a reward-ad SDK, and an offerwall SDK — moving receipt-recognition preprocessing from the server to the client. Also implemented Naver OAuth 2.0 login and a module wrapping Google Play In-App Review and Apple StoreKit `requestReview` behind a single API, in Swift/Objective-C and Kotlin.
Data Layer and Quality Operations
- Unified four analytics SDKs (Amplitude, AirBridge, Notifly, Firebase) behind a single `Analytics.track()` interface, migrated 30+ files off direct SDK calls, and pinned the event taxonomy to a codegen contract that gates schema drift.
- Diagnosed three separate root causes behind unpaid ad rewards and designed a server-to-server callback structure. Resolved 14 user-reported incidents and introduced a process for tracking crashes as issues with a shared error-reporting layer.
Other
- Established testing, technical documentation, and CI automation foundations, leaving onboarding documentation and quality gates for future changes. Authored 144 pull requests in 82 days and shipped 139 of the 220 Jira issues I owned or filed.
Led the 0-to-1 launch, operational stabilization, and continuous improvement of a Flutter (iOS/Android) app for a pet behavior/personality-type assessment and expert consultation platform.
Payment Policy and PortOne
- Resolved payment/policy issues (Apple review/payment policy) and built three PG payment integrations on PortOne, laying the groundwork for launch and B2B/B2G expansion.
- Worked directly with Apple Developer Relations to clarify the service model (domestic-only, offline brokerage) and resolve App Review and payment-policy issues.
- Standardized the payment flow on PortOne and developed and published the `portone_flutter_v2` package (180+ pub.dev downloads in the last 30 days as of September 2026).
- Led contracting and integration for three payment gateways (Toss Payments, Toss Pay, Kakao Pay).
Product Architecture and UI/UX
- Structurally managed state, model, and routing complexity using Riverpod, Freezed, and go_router.
- Achieved 85%+ positive responses for UI/UX in a user satisfaction survey.
Observability and Product Data
- Built an observability system connecting crashes, logs, and behavioral data for incident investigation and funnel/retention analysis.
- Built unified logging on Sentry + Crashlytics so crash and error records could be used to investigate incidents.
- Linked analytics, session recording, and event logs by user identifier to lay the groundwork for funnel/retention analysis.
Web Operations and Deep Links
- Reliably handled complex entry/return flows with URL-based routing.
- Standardized the install/deep-link experience across iOS and Android using Universal App Links.
- Built a non-developer editing/publishing workflow that reduced content operations time.
Wegooli is a mobility startup that has developed a car-sharing platform for public housing residents, including Bucheon's Ministry of Land smart-city project, among others.
Flutter App Launch
- Led a rapid response to the existing app's Android SDK issues and the launch of a new Flutter app, improving overall app quality and performance.
Figma Design System
- Rapidly built a componentized UI on a Figma design system, cutting development time by more than 30%.
Gbike is a mobility startup that operates the electric kickboard sharing service 'GCOO' across 50 cities domestically and internationally.
Directly developed a React Native module that subscribes to real-time gait data computed from each device's supported sensors.
Gained performance-optimization experience by directly using modern native module architectures and performance-monitoring tools such as Turbo Module, Hermes, and Flipper.
Cross-Platform Pedometer Module
- Developed a native module that combines iOS's CMPedometer and Android's SensorManager to process step-count data in a unified way across platforms.
- Improved measurement accuracy by applying the AOSP step-detection algorithm to low-level accelerometer data, to support devices down to Android API 19.
- Built on a React Native Turbo Module-based architecture to reduce the JS-Native bridge bottleneck and improve response latency.
- Monitored and optimized memory usage and runtime behavior using Hermes/Flipper-based performance tracing.
Bside Korea is a shareholder-activism platform that lets minority shareholders in invested companies act together through shareholder verification, consolidation, and electronic signatures.
Cross-Platform Product Architecture
- Took part in overall development of the Flutter-based app and the RedWoodJS-based web app, understanding and implementing requirements on both the backend and mobile sides.
- The Flutter app was designed around proxy-voting delegation during the season, and automated shareholding verification and lounge-gathering features in the off-season.
- Implemented advanced data-integration features via Kotlin/Swift-based native functionality and a GraphQL API.
Electronic Proxy Voting
- Using Flutter, built a service that collects electronically-signed proxy votes from minority shareholders for a specific stock during a campaign and delivers their consolidated opinions to the asset manager through the shareholders' meeting.
- Built the main components using Flutter's Material UI and official packages, and implemented ID card photo capture, e-signature storage, and voting for proxy delegation.
- Over 1,500 users participated in the actual proxy-voting delegation process, recording an average user feedback satisfaction score of 4.5.
Native Authentication Integration
- Wrote native bridge code in Kotlin (Android) and Swift (iOS) to integrate with external scraping and the accredited-certificate (공인인증서) module.