Uh? Mechanical things, he keeps building himself suits, and keeps making things that almost kill us. Computers, he builds those it even talks to us. He's basically the go to guy for really good technology.

[Clint never really paid all that much attention to what Tony ever made, he just knew that it would work, try to kill them, or not work until it was fiddled with.]

I do know he doesn't like it when you use his equipment to make kettle corn.