The predictive power of a single interview with a single person is just not that high. For one thing, the company is not the only one doing the interviewing; t

The predictive power of a single interview with a single person is just not that high. For one thing, the company is not the only one doing the interviewing; the candidate is also interviewing the company. Before making a commitment to join a team, I think it's valuable to speak to a number of members of that team to get a sense of what they're like. On the company side, I have also witnessed several people who might have looked alright in just one interview, but when exposed to several it became clear they were adjusting their story significantly for each interviewer to the point of dishonesty. There is clearly some line beyond which more interviews would present seriously diminished returns, but I think six or seven interviews, each 30-60 minutes, is much more likely to result in a better outcome for a professional engineering position than just one interview with a hiring manager.