Product Backend Engineer
Java/Spring Boot APIs for authentication, authorization, state transitions, transactions, and database-backed service rules.
SO JUNG LEE
Backend engineer focused on product services. I build Java/Spring Boot and Python/FastAPI backends around authentication, state transitions, transactions, cache, API contracts, and reviewable AI/OCR data boundaries.
Target roles
AI Service Backend
AI/OCR results handled as uncertain input until schemas, review flow, warnings, and final-save boundaries make them safe.
Platform & Operations
Deployment-oriented backend practice with Docker, AWS, GitHub Actions, HTTPS routing, VPS operation, and recovery notes.
Project evidence
These are learning and team-project experiences, written conservatively and without overstating professional seniority.
ALLPICK · Admin and user service flows
Worked on admin and mypage flows where members, sellers, and admins touch the same data. Focused on role boundaries, status transitions, exception rules, and screen-to-server consistency.
Java
Spring Boot
JPA
BusinessException
MySQL
BOUT · OCR and AI review flow
Designed a flow where OCR output is reviewed and corrected before becoming a saved purchase or warranty record. The key concern was not just generating AI output, but making it safe to use.
FastAPI
PostgreSQL
OCR
OpenAI API
TFTgogo · Java/Spring cache, concurrency, and social login boundaries
Reviewed backend risks around cache invalidation, party capacity concurrency, chat permissions, and social account ownership. The focus was keeping backend rules aligned with UI behavior.
Spring Boot
Java
Spring Security
MySQL
Redis
Personal VPS · Deployment and documentation system
Operate a personal Ubuntu VPS with HTTPS, domain routing, Obsidian sync support, and a private automation agent environment. This page is deployed on that server.
Ubuntu
Apache
Let's Encrypt
Obsidian Sync
How I work
My strongest habit is turning uncertain implementation work into readable steps, checks, and notes.
Read the flow first
I try to understand existing files, API shape, and user flow before adding code.
Keep claims checkable
I prefer concrete project evidence over broad claims like “problem-solving skills.”
Write to learn
I use blog posts, notes, and implementation guides to make decisions visible.