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Highlights

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@nushackers @nusmodifications @NUSGreyhats @CAPTxTreeckle @ItzyBitzySpider

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jloh02/README.md

GitHub Stats

About Me

I'm a hacker (in both senses, probably) who builds at the intersection of hardware and software, occasionally dabbling in cybersecurity. I like shipping things that make life a little easier — whether that's a venue booking system, a transit router, or a challenge that makes you stare at a memory dump at 2am.

Elsewhere: Blog · LinkedIn · CTF writeups · Robotics portfolio


Highlights

Cybersecurity & CTF

2nd BrainHack CDDC 2024 — DSTA Inter-Uni Capture-the-Flag
3rd STACK the Flags 2020 — GovTech 48-hour jeopardy CTF
Silver National Olympiad in Informatics 2020
Award Cyberthon 2020 — 3rd overall & Data Science category

Hackathons

1st + Most Innovative STACK the Codes 2022VulnGuard VS Code extension
Most Entertaining Hack&Roll 2023Attention, PvP maze game (Socket.io backend)
Top 8 Hack&Roll 2022CAPSLOCK, 1v1 typing game (high school participant)

Robotics & Hardware

3rd + Math Division Champion VEX Robotics World Championship 2019 — Division Champions, Round Robin Finals
1st + Excellence Singapore VRC National Championship 2019
Silver Zhang Heng Engineering Award — FIRST Global Challenge 2019 (Team Singapore)
Custom Arduino Protocol SICC — custom half-duplex serial protocol for reliable Arduino IC communication

Academic & Community

NUSMods NUSMods (source) — Maintainer (2023–2025)
Treeckle Treeckle (source) — Tech Development Head, venue booking for CAPT (~100 MAU)
CAPT Mass Recruitment Led tooling for 20+ committees, 200+ applicants (bot)
Greyhats × CNA Built screen-recording tooling for Talking Point: repair shop privacy

CTF Challenges I've Authored

Challenges for NUS Greyhats events — full list on my blog.

Hackbash 2024

Walk Down Memory Lane Volatility memory forensics, process analysis, and file carving from a Windows dump

GreyCTF 2024

Maze Runner Use dijkstra to solve a maze problem where you can phase through walls
Poly Playground Derive polynomial coefficients from their roots
All About Timing Predict tokens seeded from connection time in seconds

Welcome CTF 2025

NUS Geographer Decode Bluey's NUS walk diary into a hidden message

GreyCTF 2025

Rainbow Road Abuse WebSocket disconnect state to bypass maze walls (source) · writeup

GreyCTF 2026

67 Reach score 67 in server-verified hand-gesture Flappy Bird
SeeTeeEffedIn PostgreSQL refint cascade SQL injection
Go Going Goen Chain PostgreSQL READ COMMITTED race conditions across three stages

Technical Journey

Robotics & embedded

VEX Robotics Portfolio (2015–2020) — multithreading, PID, odometry
RoboCup Robot Soccer 2016–2017
Arduino / SICC SICC protocol (2016–2020) - A custom synchronous protocol for inter-IC communication based off I2C

Backend & infrastructure

SGRouter Java / Spring (2017–2021) — multithreaded Dijkstra transit routing
Valorant presence Golang backend

Frontend & desktop

Android 2017
Flutter 2018–2021
Valorant chat client Vue + Electron + Vite (2022)
NUSMods · Treeckle NUSMods · Treeckle

Security, ML & misc

Capture the Flag Competing & authoring (2018–present)
Machine learning 2019–2020
Valorant presence C++ Windows + Discord (2021)

Pinned Loading

  1. VEX-Worlds-2019-8059A VEX-Worlds-2019-8059A Public

    VEX Robotics World Championship Code for 8059A (Math Div Champs; RR 3rd Place)

    C++

  2. SICC SICC Public

    A custom half-duplex 2-wire integrated circuit communication protocol developed for an Arduino system

    C++

  3. SGRouter SGRouter Public

    A backend application for public transit routing in Singapore

    1

  4. nusmodifications/nusmods nusmodifications/nusmods Public

    🏫 Official course planning platform for National University of Singapore.

    JavaScript 671 357

  5. capt-laundry-bot capt-laundry-bot Public

    Python 1 6

  6. nus-notes nus-notes Public

    C 3