Hi, I'm
Software Engineer
Five years of experience shipping mobile apps to over 100 million users. I write clean Kotlin, build solid CI/CD pipelines, and use AI tools to move faster.
I am a Software Engineer in Seoul with five-plus years shipping mobile apps to over 100 million users. I write clean Kotlin, build production-grade CI/CD pipelines, and use AI tools as part of my development workflow.
At Retrica I develop and ship features for the Retrica camera app (100M+ downloads), built the Android version of Acha AI from scratch, and designed an agentic E2E testing platform that runs the mobile app on real Android devices and iOS simulators on every pull request. At PeopleInNet I built Android clients and backend integrations for the VitaMatch and Postcare health apps.
Before that I worked on automotive, wearable and kiosk systems for Hyundai Mobis, HMC and KMenu: hardware integrations, real-time protocols and payment flows that had to work the first time.
What I work with day to day, grouped by area.
Kotlin
Java
Jetpack Compose
Android SDK
Flutter
Dart
WearOS
Python
FastAPI
Node.js
Docker
GitHub Actions
CI/CD
REST
GraphQL
WebSocket
MQTT
Firebase
Claude API
OpenAI API
Gemini API
Prompt design
Agentic E2E testing
Git
Linux
C
ADB
WebDriverAgent
Figma
Jira
Slack
Three things I'm proudest of, then everything else.
A digicam filter camera app with 100M+ downloads on Google Play. I develop and ship new features on the Android codebase — camera pipeline work with CameraX, Kotlin, and Jetpack Compose, deployed through a CI/CD pipeline on every PR.
Kotlin
Jetpack Compose
CameraX
An AI photo generator that turns selfies into cinematic portraits. I built the Android app from scratch — architecture, Jetpack Compose UI, API integration, and Play Store deployment. 10,000+ downloads since launch.
Kotlin
Jetpack Compose
AI
A CI/CD platform that runs the mobile app on real Android devices and iOS simulators on every pull request. I built the orchestrator, GitHub Actions integration, device runner, and the web console that surfaces screenshots, video, and logs as evidence per PR.
Claude Code
Python
GitHub Actions
Android
iOS
Health AI agent that recommends supplements and manages medication schedules. I built the RAG pipeline over the product and nutrition knowledge base, the reminder and calendar tools the agent calls, and the Jetpack Compose client.
Kotlin
Jetpack Compose
AI agent for Wonju Severance Hospital that answers post-surgery patients from official hospital protocols. I built the retrieval pipeline that grounds every answer in the protocol documents, the agent's tools, and the Android client.
Kotlin
Jetpack Compose
In-vehicle control app for HMC: rear-seat entertainment, seat adjustment, lighting and projector functions driven over a local MQTT network.
Kotlin
Jetpack Compose
MQTT
Multi-module Android and WearOS tool for the Hyundai Mobis research team. The watch collects Samsung Health SDK and sensor data and streams it over Bluetooth to the phone, which processes and stores it for sleep research.
Kotlin
WearOS
Samsung Health SDK
Bluetooth
Hyundai Mobis accessibility project for drivers with disabilities. The app talks to the main vehicle controller to drive media, navigation and LED systems, with screen mirroring, touchpad control and TTS voice feedback for hands-free use.
Kotlin
TTS
Screen Mirroring
Kiosk, table order, tablet POS and waiting-list modules for restaurants. I integrated the kiosk payment module, real-time menu updates over WebSocket, order placement and receipt printing.
Java
Kotlin
WebSocket
Payments
