To spot a top performer one needs no elaborate testing or, god forbid, standardized interviews. It is the same as it is in sports or music or arts - there are cues that identify a top performer. What standardized tests you want to apply to, say, Beethoven, Orwell or Muhammad Ali, or, good forbid, Steve Jobs, or Igor Sysoev?)

It is not about testing, it is about having a gift (or not) and a character - willingness to become a master just for the sake of ones love/passion/enjoyment of the craft, not any stupid job or position.