In the setting of an interview: What is the best way to reliably identify when somebody is an excellent programmer. By this I mean he is one of those that is 10-15 times more efficient / rapid / better than  his peers towards the lower end of the spectrum. Many of us have heard of the FizzBuzz Problem as a way to weed out the weak ones. Certainly, taking 5-10 minutes to solve that problem is a serious indicator that an applicant is a weak candidate. I posit that a good indicator is being able to solve that as quickly as you can write. This doesn't seem sufficient, though.Is it maybe something like giving him a moderately complicated buggy program, and seeing how fast he can grok it and identify all the problems with it?
What is the best way to discern an excellent programmer in a job interview?
language agnostic;interview