a person with skills or knowledge related to technology, especially computing; information technologist.

What are techies called?

A person with a strong interest or skill in computers or technology. geek. hacker. nerd. programmer.

Which is correct techy or techie?

In informal|lang=en terms the difference between techie and techy. is that techie is (informal) a person who works on the technical side of events while techy is (informal) technical.