Interviewing should normally have two results: the candidate was able to demonstrate the appropriate skills, or the candidate was not. Not being able to demonstrate the right skills in the interview does not mean that the candidate is a bad programmer or even a bad fit for the job. It just means that I was not able to verify their bona fides in that hour.
That's the difference between "that interview didn't go well" and "you are a bad programmer." One's a major blow to self confidence, and the other's a bummer. It's also a helpful mindset shift for both the interviewer and the interviewee: both of us are working together to achieve the goal of proving your capabilities. My job is to give you as many opportunities as possible to do so.
Why do you think that whenever we discuss interviews on HN, there's several highly upvoted comments complaining about how many incompetent people show up for interviews and how this basically makes coding interviews necessary?
I think it's because most interviewers consider people that failed their interview bad programmers.
You get classroom training, shadow hours, supervised hours, and certification on a particular type of interview. From that day forward any open slot on your calendar is fair game for Recruiting to schedule, up to 3 per week. You might get away with a "No" RSVP if you have a good excuse, but not in general. It's part of your job.
