// JUNXIONG.DEV / SINGAPORE
Ong Jun Xiong
I'm a software engineer at TikTok in Singapore, building AI infrastructure for e-commerce.
At TikTok I built my team's shared AI platform from zero: an agent service, an MCP server over the data warehouse, and a React SDK for AI chat. Before that I wrote Go services for the seller platform. Outside work, I built and ran Compoze until a client bought it. Below is what I build on my own time.

JX / 2026
SINGAPORE
// PROJECTS
Selected work
Open source · 2026
Groundplane
I built Groundplane to catch cases where an agent gives the wrong winner or total despite having the right data. It checks the answer against recorded tool results.
Declared field
Check 01
- Claim
- north
- Recorded winner
- harbour
Blocked · UnsupportedClaim
The model named north, but the recorded facts rank harbour first, so the field is rejected.
Company · 2025
Compoze
I ran Compoze alongside TikTok, building assistants that answered questions from company documents. I handled sales, development and customer training.
Policy search
3 sources
How much annual leave carries over?
Up to 5 days, used by 31 March.
Also building
Research system
Trading engine
I use this to test trading ideas overnight, with rules set before the results come in.
Agent skills
Skillsmith
I make a skill from the repo, then compare the agent with and without it to check whether the extra instructions help.
Agent tooling
Skillpack
The eight reusable instructions I keep in one place for Claude Code and Codex.
Design system
UI Pack
The web figures, motion rules and slide starters I reuse across my projects.
Interview practice
Jobforge
Coding drills that grade the plan I say out loud before I touch the keyboard.
// ELSEWHERE