Justin Cho

Software Engineer based in Seoul, South Korea

I build product-quality demos that remove real friction—then I prove it with a live link.

My strength is turning messy requirements into clean systems: Next.js for fast shipping + UX/SEO, Supabase(Postgres) for reliable data + RLS, and Tailwind for consistent UI at speed.

I care less about listing features and more about why the product exists, what problem it solves, and what changed after shipping.

If you are hiring, reach out via email!

EN한글

Highlights

Quest-On — AI Interactive Exam Platform

Problem → Solution → Impact → Demo

Problem: Grading open-ended reasoning is slow and inconsistent.

Solution: Built an AI-assisted exam flow that captures clarification, feedback, and rubric-based scoring.

Impact: Reduced grading workload by ~80% (10 hrs → 2 hrs) through automated scoring + rubric feedback.

Demo:

Live
3D Printer Management System

3D Printer Management System — Campus-wide Operations Tool

Problem: Students used printers without proper logging, and staff lacked real-time visibility & issue tracking.

Solution: Built a campus-wide status & reservation system with real-time monitoring, queue management, and a professor dashboard.

Impact: Used by ~400 students/semester; improved accountability and reduced "unknown usage" cases.

YouReview

YouReview — Rank & Share Culture

Problem: Personal rankings for films/music/books are scattered across notes and screenshots—hard to share and revisit.

Solution: Built a clean web app to rank, organize, and share lists publicly at youreview.me.

Demo:

Live

Projects

Quest-On — AI Interactive Exam Platform
Problem: Grading open-ended reasoning is slow and inconsistent.
Users: Professors and TAs running exams that require structured reasoning and fast, fair evaluation.
Key Decision: Why Next.js: ship SEO-friendly demos fast. Why Supabase: reliable Postgres + Auth/RLS for permissions.
Result: Reduced grading workload by ~80% (10 hrs → 2 hrs) via automated scoring + rubric feedback.
Demo:
Live
My Role: Co-Founder, CPO & Lead Engineer (end-to-end).
3D Printer Management System — Campus-wide Operations Tool
Problem: Students used printers without proper logging, and staff lacked real-time visibility & issue tracking.
Users: Students reserving printers and staff/professors managing availability, queues, and incidents.
Key Decision: Built for real-time status visibility and operational accountability (monitoring + queue + dashboard).
Result: Used by ~400 students/semester; improved accountability and reduced “unknown usage” cases.
My Role: Built end-to-end (full-stack).
YouReview — Rank & Share Culture
Problem: Personal rankings for films/music/books are scattered across notes and screenshots—hard to share and revisit.
Users: People who want clean, public lists to organize tastes and share recommendations.
Key Decision: Why Next.js: fast iteration + product-like UI/SEO for sharing. Why Tailwind: consistent UI at speed.
Result: Shipped a live, shareable ranking site at youreview.me with public links for instant evaluation.
Demo:
Live
My Role: Solo developer (product + design + engineering).
Portfolio Website — Modern, product-like personal site
Problem: Recruiters need a fast way to evaluate scope, decision-making, and proof via demos.
Users: Hiring managers and engineers reviewing work quickly.
Key Decision: Why Next.js: performance + SEO. Why Tailwind: rapid iteration with consistent UI.
Result: Clear, demo-forward layout optimized for quick scanning and immediate evaluation.
My Role: Built and iterated independently.

Experience

Quest-On — Co-Founder, CPO & Lead Engineer
Seoul, Korea · Aug 2025 – Present
  • Built and shipped a full-stack AI assessment platform end-to-end (Next.js, Supabase, OpenAI), launching an MVP in 3 months.
  • Reduced grading workload by ~80% (10 hrs → 2 hrs) by implementing rubric-based scoring and automated feedback generation.
  • Designed a 4-stage LLM interaction engine to evaluate reasoning in real time (clarification → guidance → draft → rubric feedback).
  • Ran 2 live AI copilot exams with 20+ students and maintained stable operation without major incidents; collaborated with 4 professors to align product and pedagogy.

Awards

KoreaIT Academy — Web Service Development Competition 1st Place
2025
SNAAC (Seoul National University Accelerator) — Advanced to Final Round (Pre–Demo Day)
2025
Startup Express (Korea University) — Advanced to Final Round (Pre–Demo Day)
2025