I am a jack of all trades in technology; know a little bit about a lot. Embedded systems, signal/image processing, Internet of Things, measurement technology, and several different fields in science. I can do everything from designing an embedded system from the PCB level up to writing a web user interface for it, but I do not claim to be a top expert in any of those fields.
I do have a PhD in technology and some academic background. It does not make me any wiser or my answers any better, but it has left me with a subtle tendency to try to find the theoretical background behind practical problems. Sometimes it helps, sometimes it slows things down.
So, as a SO contributor I'm from the shallow end; for most things there are better specialists around. But sometimes they are just too busy to answer :)