Research
Ask what a system reveals—and under which assumptions.
The person behind the work
Ideas need a builder.
I’m Changjian “CJ” He—an AI researcher, applied mathematician, and founder connecting rigorous questions with practical systems.
CHANGJIAN “CJ” HE
Think precisely. Build practically.
I work where machine learning security, data infrastructure, and product execution meet. Mathematical structure helps me frame a problem; building a working system tests whether that framing holds.
Explore the workThree ways of working.
Engineering
Turn a technical idea into a workflow people can inspect.
Product
Let real constraints shape what is useful to build.