Projects

Personal projects built for my family, client projects shipped to production — from AI-powered learning platforms to Chrome extensions and multi-agent systems.

Web App Client rundna.online

RunDNA

Runners don't just need data — they need to understand their running identity. I built an AI system that decodes it from Strava.

AI-powered running analytics platform. Connect Strava, discover your 5-axis runner personality, chat with an AI coach, generate race plans, and share weekly reports. Bilingual (EN/KO).

Next.js 16 React 19 TypeScript Supabase Strava API +2

Web App Client promptgarden.online

Prompt Garden

The client needed prompt engineering to feel like design, not guesswork. So I built a visual IDE for it.

Visual prompt engineering workspace. Build, connect, and test AI prompts with a node-based editor. Shipped with custom domain.

React 19 TypeScript xyflow Zustand Tailwind CSS v4 +1

Web App Client engreading.com

EngReading

v5.0 — Korean sentence in, English brain out. AI classifies your verb into 1 of 7 Sets and animates how a native speaker builds the sentence left-to-right.

Forward-Flow English Brain Rewiring Engine. Input any Korean sentence, AI classifies the core verb into 7 Sets and animates the native English thought process. Gamified with XP, streaks, radar mastery charts, and SM-2 spaced repetition review.

Next.js 16 TypeScript Fireworks AI Supabase Tailwind CSS v4 +2

Concept Client

Running Club Analytics

Building the club version — individual engine is live with 170+ runs of real data. Partner needed for scale.

Strava-connected club analytics platform — member rankings, group pace optimization, injury prevention monitoring, and GPS-based meetup recommendations. Proof of concept running with real data.

Astro SSR React 19 TypeScript Supabase Strava API +2

Concept Client

Enterprise Decision Agent Team

Building for a client — AI departments that debate enterprise decisions so humans don't have to go in circles.

Multi-agent decision simulation where AI agents with conflicting KPIs debate enterprise decisions through structured analysis, cross-critique, and consensus. Live demo with automotive industry scenario.

Astro React 19 TypeScript Multi-Agent AI Tailwind CSS v4

Web App Personal

SAT Crusher

My kids needed SAT prep. Every app tracked right/wrong — none asked why. So I built an AI tutor that does.

Adaptive SAT prep platform with 8 AI tutor modes, spaced repetition, and wrong-answer DNA analysis.

React 19 TypeScript Supabase Fireworks AI React Router v7 +3

Web App Personal

Family Reading Journey

Our family reads together every day. Not to compete — but to grow. I built a platform that makes shared reading a family adventure.

Family reading growth platform with reading journey tracks, radar analytics, AI coach, book reviews, reading letters, and cooperative achievement badges — powered by Supabase realtime.

React 19 TypeScript Supabase Zustand 5 Tailwind CSS v4 +2

Concept Personal

Claude Writer

What if your note-taking app could think? I built an AI writing assistant that lives inside Obsidian's sidebar.

Obsidian plugin that transforms your notes with Claude AI — rewrite, restructure, translate, explain at 4 depth levels, and auto-generate Mermaid visualizations. All powered by Claude Code CLI.

TypeScript Obsidian API Claude Code CLI Mermaid esbuild

Mobile App Personal Google Play

NeuralMind

I wanted a tool that maps how ideas connect — not just stores them. ML turns raw thoughts into visual knowledge graphs.

ML-powered mind mapping app that visualizes thought flow and concept relationships with an intuitive graph interface for Android.

Kotlin Jetpack Compose Material Design 3 Machine Learning Room DB

Chrome Extension Personal

The Parasite

My kids watched 200+ YouTube Shorts a day. Every blocking app failed. So dad built a parasite.

Chrome extension that fights YouTube Shorts doom-scrolling with tamagotchi evolution, achievements, and progressive lockdown mechanics.

TypeScript Chrome Extension API esbuild Manifest V3

Mobile App Personal

Smart Memo

My kids' study notes were scattered across notebooks, phones, and sticky notes. AI should organize this.

AI-powered memo app with intelligent categorization and clipboard analysis for Android.

Kotlin Android SDK Room DB Material Design

Mobile App Client

Word Master Pro

The client wanted vocabulary from real reading, not random word lists. Clipboard captures + spaced repetition.

Vocabulary learning app with clipboard analysis and spaced repetition for Android.

Kotlin Android SDK Clipboard API Material Design

Web App Client

Investment Agent Swarm

The client wanted 4 AI analysts debating the same stock in real-time. I built the boardroom.

Multi-agent investment analysis platform where 4 specialized AI agents collaborate to provide comprehensive stock analysis across US and Korean markets.

React 19 TypeScript Fireworks AI Zustand 5 lightweight-charts +2

Web App Personal

Planner 2026

My kids forget what they studied yesterday. So I built a calendar that remembers for them — on Day 1, 4, 7, and 14.

Ebbinghaus forgetting curve-based review calendar that auto-generates D+1, D+4, D+7, D+14 spaced repetition schedules from study logs.

React 19 TypeScript Zustand 5 Recharts Tailwind CSS v4 +1

Web App Client

Agentopia

The client wanted AI agents that fight each other. I built the colosseum.

Meta social strategy simulation where AI agents debate, compete, and evolve. 8-stat personality tuning, 5-turn live debates, AI judging, ELO ranking, and a BYOK economy system.

Next.js 16 React 19 TypeScript Supabase Fireworks AI +3

Web App Personal

English Chain

Your day is an English textbook. Choose your morning, pick your commute, decide your dinner — every choice branches into different conversations.

Choose-your-own-day branching English conversation app with 87 situational cards, 8 choice points, 4-stage learning per card, and a unique journey map fingerprint for every playthrough.

React 19 TypeScript Zustand 5 Framer Motion Tailwind CSS v4 +1

Web App Personal

Super Mario Bros

A pixel-perfect Super Mario Bros clone built from scratch with pure TypeScript and Canvas API.

Classic side-scrolling platformer with tile-based levels, physics engine, sprite animation, enemy AI, and sound effects — no game engine, no dependencies, just TypeScript and HTML5 Canvas.

TypeScript Canvas API Vite

Web App Personal

Sky Combat

3D aerial dogfight game built with React Three Fiber — fly, shoot, survive the waves.

Browser-based 3D combat flight game with physics-based flight controls, enemy AI squadrons, weapon heat management, explosions, contrails, and procedural terrain — powered by Three.js and React.

React TypeScript Three.js React Three Fiber Zustand +2

Web App Personal

증상 구조화 도구

환자의 "화끈해요"를 의사가 읽는 언어로 바꾼다.

의사-환자 정보 불균형 문제를 푸는 헬스케어 도구. 환자가 증상 부위·성격·악화 완화 패턴을 4단계 위저드로 입력하면, 3가지 가능성 분석(근골격계·신경·유방)과 진료 시 바로 보여줄 1페이지 리포트를 생성한다.

HTML Vanilla JS Tailwind CSS CDN Vercel

Web App Personal

PostSpark

ChatGPT forgets you. PostSpark remembers your professional story — and gets smarter every session.

AI-powered LinkedIn content strategist that learns your style over time. Input your professional background once — get 10 personalized post ideas with full drafts, a 2-week content calendar, and a style engine that improves with every session based on what you like.

HTML Vanilla JS Tailwind CSS CDN Fireworks AI Vercel

Web App Personal

IdeaForge

Your frustrations are saved. Your taste is learned. Each session the ideas get sharper.

AI business idea generator that remembers your pain points and learns what kinds of ideas you like. Input your frustrations once — get 10 business ideas with revenue models, 2-week MVP scope, competitive moat, market potential, and why-now analysis. Stars the ideas you love; learns your preference patterns over time.

HTML Vanilla JS Tailwind CSS CDN Fireworks AI Vercel

Web App Personal

My Daily Diary

Sometimes the simplest apps carry the heaviest thoughts. No backend, no login — just you and your words.

A minimalist web diary app with mood tracking, photo attachments, dark mode, and full localStorage persistence — built as a single HTML file with React and Tailwind CSS.

React 18 Tailwind CSS LocalStorage Babel

Web App Personal

SentenceFlow

135 sentences across 5 levels and 8 categories — 7 new ones unlock every morning at 7 AM.

English sentence memorization engine with 5 CEFR-aligned levels, 8 real-life categories, Progressive Chunking Recall, SM-2 spaced repetition, daily 7AM unlock system, and memory strength dashboard.

React 18 Tailwind CSS LocalStorage SM-2 Algorithm Web Speech API