Projects

In-depth write-ups of production services and larger projects.

Featured projects

Production

Backend / Infra (led a 3-person team) · 2026.02 ~ 진행 중

A production Online Judge used in PNU’s mandatory course (~800 users). Owned infra & backend and led a 3-person team.
Designed and built a local-LLM (vLLM) AI tutor, tuned via Locust load tests to serve 30 concurrent users within 3 seconds.
Ran the K3s cluster directly, diagnosing production incidents (crash-loops, a CNPG WAL runaway) down to root cause.

In production

Full-stack (planning, development, operations) · 2026.02 ~ 진행 중

Consolidated scattered spreadsheets — company data, internships, industry outcomes — into one web system, now used in production (aicms.pusan.ac.kr).
Built solo end to end on Next.js and PostgreSQL: data modeling, features, and deployment.
Migrated from cloud (Vercel + Supabase) to an on-campus self-hosted server with Caddy HTTPS and GitHub Actions auto-deploy.

Serverless CMS

Solo architect & full-stack developer · 2026.05 ~

Designed and built solo a zero-install CMS where non-developer staff create print-grade brochures with one line of Markdown, auto-deployed on save.
Implemented auth, collaboration locking, and CI/CD using only the GitHub API and git commits — no backend, no DB.
Prevented concurrent-edit conflicts with a distributed Soft Lock built on .locks commits.

Hackathon

Development (backend, app, deployment) · 2025.05 ~ 2025.08

A mental-health app that analyzes journal emotions with GPT (Plutchik’s wheel) and links students to campus counseling when negative emotions persist for 7 days. Encouragement Award, 6th PNU SW Hackathon.
My first app project — built and deployed a FastAPI/MySQL backend and a Flutter cross-platform app.
Designed a consent-based token-snapshot scheme for safely sharing 7-day journal summaries, and a layer-based rendering system for placing items in the "mind garden".

Bootcamp

Backend · 2025.02

At a LikeLion backend bootcamp (70h), built the backend of a second-hand marketplace modeled on Karrot.
Applied JWT auth, RESTful APIs, and sessions with FastAPI, Redis, SQLAlchemy, and pydantic.
My first project built with official docs only (no ChatGPT) — learned to debug relentlessly.

Capstone

RL & simulation · 2025

A graduation project training a car to park itself with the PPO algorithm inside a Unity simulation.
Wired the physics simulation to the training pipeline via Unity ML-Agents, iterating on reward design.
The implementation is modest, but the final report carefully documents the problem framing, approach, and experiments.