Obviously, you're free to ask this question. I wouldn't like it, but it's hardly outrageous. I'm free to decline to answer if I choose. I would say one thing

Obviously, you're free to ask this question. I wouldn't like it, but it's hardly outrageous. I'm free to decline to answer if I choose. I would say one thing here, though… if the candidate is active on github, maintains a technical blog, and perhaps has done some speaking at conferences or meet ups with video links, it doesn't look great when the interviewer asks this question (are you a good programmer?). It may imply that the interviewer 1) hasn't bothered learning much about the candidate, or 2) is unable to learn much about a candidate and/or isn't able to assess the information. I know this is an extreme example, but would you ask bob dylan "are you a good songwriter?" Or even a more obscure person who still has a fine presence on the web. It's like, uh, my work is right there, have you listened to it?