In 50 years of programming I've worked with a few. One characteristic is a deep understanding and command of all that they touch. For example, I worked with Bill Schelter (GNU Common Lisp). In 1980, prior to the Internet, we were working on a problem (tail recursion). He was using the emacs editor and he found a bug. Bill stopped what he was doing, fetched the sources for emacs (using ftp), found the source of the bu…
In my experience the most brilliant people aren't brilliant individually or brilliant as a team player or brilliant at X or brilliant at Y, they're simply brilliant. The one exception to this observation, in my experience, is that I've met a few brilliant mathematicians who are very narrowly brilliant.