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Hi, my name is

Jack Chang

Exploring how software and algorithms shape intelligent systems.

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About Me

Nice to meet you! I’m Jack, a CS grad from UC Irvine, mainly interested in AI/ML adjacent work and hardware + software. Here's how I got to where I am:

  • At age 12, I created a cash-tycoon game on Scratch, and quickly got 2,000+ plays on it. Shortly after I wrote my first lines of real code, a browser-based treasure hunting game.
  • In high school, I found I loved thinking hard to solve problems, and delved into competitive programming while also starting to play chess. Made USACO Gold at the 2020 US Open, and became the president of my high school's Programming and Problem Solving club. Also reached 2200 online chess rating.
  • At UCI I found machine learning and computer vision, hooked on problems where a model has to justify its answer, not just produce one.
  • That led to projects like Rookie, a T5 model I trained to explain chess moves that chess players preferred over GPT-4o-mini 73.7% of the time. And Orion, a threat assessment simulator where an AI advisor has to justify every risk score it assigns.
  • Now I break a constraint solver for a living. 80+ defects found so far.

Happy to talk tech, chess, or anything else you have in mind! Reach me at or send me a message on .

jack

Work Experience

AI Tech Knowledge

San Diego, CA

Software Engineer

June 2026 - Present

I design end-to-end and branch-coverage test suites for a constraint-programming scheduling engine, which surfaced 80+ latent solver defects and raised coverage across critical modules from 63% to 97%.

From that work I've shipped 50+ solver-correctness fixes using test-driven development and root-cause analysis, sequencing changes from low to high risk so production stayed stable throughout.

Part-Time Software Engineer

June 2023 - September 2024

I raised throughput on scheduling-optimization workloads by 50%+ by writing multithreaded C++/Python modules on top of Google OR-Tools, which handled constraint solving and model queueing.

I also built the desktop side of the product: a cross-platform Node.js service that queues, executes, and monitors AI inference tasks, an Electron.js auth client backed by Supabase, an auto-updater, and Windows/macOS installers tying them together. GitHub Actions CI/CD automated the builds and cut 20+ minutes off every release.

MetaGuru

Taipei, Taiwan

Research Scientist Intern

June 2023 - November 2023

I built an internal Q&A assistant in Python on the GPT-4 API that answered employee HR policy questions, cutting repetitive policy lookups by 15%.

Before building it I compared three deployment approaches: prompt engineering, fine-tuning feasibility, and how the model handled English and Mandarin. I recommended a prompt/RAG prototype so we could iterate faster and maintain less.

NexStream Technical Education

San Diego, CA

CS Curriculum Developer & Instructor

May 2022 - May 2023

I designed and taught 5 courses in computer science, contributing to a 10%+ increase in student enrollment:

  • Intro to Pygame, taught in Summer 2022
  • Advanced Pygame, taught in Summer 2022
  • Bronze level USA Computing Olympiad logic and algorithms course, taught in the 2022-2023 school year

All courses can be found here

Intern Data Scientist

Jan 2022 - May 2022

I built the company's first learning-visibility system: a JavaScript xAPI event pipeline feeding Watershed's Learning Record Store, capturing 20+ activity events so instructors could see student engagement across every course offering.

I then wrote Python analysis tools that scored student progress and open-ended response accuracy, removing 3+ hours of manual course review each week.

Good Trouble

San Francisco, CA

Gameplay Programmer Intern

Oct 2022 - March 2023

On an unreleased combat racing game built in Unity and C#, I owned the weapon aiming system and UI controllers, working with Unity's then-new Input System for gamepad support and UIToolkit for the interface layer.

I cut projectile performance overhead by 50% by replacing per-shot instantiation with object pooling for reusable weapon systems, profiled against both PC and Xbox targets.

Some Things I've Made

Rookie chess commentary preview

Rookie: AI Chess Commentary Generator

Project Lead

A fine-tuned T5 model that turns Stockfish engine signals into grounded natural-language move commentary, preferred over GPT-4o-mini by 73.7% of human evaluators.

Hugging Face Github

Orion: AI Threat Assessment System

Sole Developer

A full-stack threat assessment simulator that tracks airborne objects on a live map, scores them against a multi-factor risk model, and pairs the score with an LLM advisor that explains it.

Live Demo Github
Orion AI threat assessment system preview
Computer Vision Pipeline preview

Geometric Computer Vision Pipeline

Sole Developer

An end-to-end classical vision pipeline (ORB feature matching, RANSAC homography estimation, inverse warping, blending) with debug tooling built to work out where alignment fails.

Github

Monte Carlo Tree Search Visualization

Sole Developer

An interactive demo that renders Monte Carlo Tree Search step by step, exposing how visit counts and value estimates converge on a decision.

Live Demo Github
MCTS Picture
Toasty Plugin Picture

"ToastyPlugin": Minecraft Dungeons Plugin

Project Lead

A Java-based Minecraft server plugin that introduces custom gameplay mechanics using an event-driven architecture designed for multiplayer environments.

Video Demo Github

Certifications & Honors

Outside of Work

Chess

I started really getting into chess during Covid, and grinded until I hit a peak rating of 2200 rapid on chess.com. At UCI I joined the chess club and ended up getting invited to play on the Pan-Ams collegiate team.

Guitar

Been playing since elementary school, so it's been over a decade now. I played in my high school's jazz band, and now I just learn whatever I find fun to play. Some of my favorite songs to play include Flower Dance by DJ Okawari, Playing God by Polyphia, and Kamado Tanjiro no Uta from Demon Slayer.

Badminton

I played tennis for many years, but stopped when Covid closed the courts. Then I tried badminton with friends my senior year of high school, and quickly found it to be my favorite sport. Now I'm mainly a singles and mixed player, participating in tournaments such as UCSD Sun God and UCI ACC.

Hiking and the Outdoors

My love for the outdoors came from Boy Scouts, where I went on many camping and backpacking trips. I love challenges and exploring new places. Some of my personal favorites include reaching the snow on Mount Rainier, braving a snowstorm in Yosemite, and backpacking through Anza-Borrego.

Get In Touch

AI/ML adjacent and hardware is where I’m most curious right now, but I’m open to software engineering roles broadly. Reach out if you want to talk about a role, a project, or anything above. I’ll get back to you!