There was a novel in which a planet had "wizards" (I can't recall if it was real magic, or ESP). They sent one of the stronger ones to "spy" on other human planets that didn't have any magic. He was able to interface with the different machines on these worlds.
I also recall that the planets were in a different dimension or out-of-phase with the rest of the galaxy, which gave them an advantage over the other alien races. The name of the main character is on the tip of my tongue. It was in English, and a paperback. It was also a decent sized book, probably around 400-450 pages, if I remember the thickness correctly. I read it around 5 years ago (2010ish). Not sure how old it was at the time, though.