$ whoami
Taejin Yi
Developer × Finance
System Trader · 15 Years in Dev
Writing code in Yeouido. Building products at the intersection of finance and technology.
View Projects ↓## About
For 15 years, I've been building products across trading systems, mobile apps, and everything in between — bridging development and finance.
Currently working as a system trader at a securities firm, where I design and develop ultra-low-latency market-making systems operating at nanosecond precision.
Outside of work, I explore the edges of technology through side projects spanning blockchain fintech, AI apps, and educational services.
## Projects
VISION
In DevelopmentVanguard and Intelligent Self-neutralizing Intermarket Order Nexus
Ultra-low-latency OMS for systematic trading. Rust-based HFT engine.
Coinluck
BuildingP2P Blockchain Fintech Platform
P2P fintech platform abstracting multiple blockchain providers through a unified interface. Provides wallet management, P2P transfers, credit unions (SOCU), and payment services.
Kimchi Hunter
LiveCEX-DEX Kimchi Premium Auto-Trading
Rust-based trading platform that tracks the kimchi premium between Bithumb and Binance in real-time, capturing spreads through automated grid trading.
끈톡
LiveAn AI messenger that joins your conversations
An AI messenger where "끈" joins your group chats and surfaces relationship insight on the spot. Shared chat rooms (multi-party and 1:1 with @mention-driven AI presence), relationship insight (per-friend personality and compatibility scores, recommended meeting days, group dynamics), and mood-based friend matching (mood chip → AI recommendation). Live on the App Store and Google Play.
Vocaid
LiveOCR-Powered Vocabulary Learning App
Vocabulary app that captures words from any screen via OCR and provides scientifically-backed spaced repetition learning with the FSRS algorithm. Capture words from Netflix, YouTube, and anywhere else.
APT톡
BuildingMap-based apartment transaction & subscription info app
Real-estate info app to explore nationwide apartment transaction prices on a map, with subscription schedules, price charts (₩/pyeong candlesticks), and AI consultation. Built on official Korean transaction & subscription open data — native iOS & Android.
오디톡
BuildingYour Personal Auditor — listens with you, points things out
A Personal Auditor that reviews medical visits with you. Records consultations and uses AI to translate jargon into plain language, builds a searchable visit archive, and prepares the next visit with missed questions and comparable alternatives. Turns patients into informed customers.