When I started my career I was in the UK civil service. One of the best things I took from that experience was the formal training they gave me in interviewing.

When I started my career I was in the UK civil service. One of the best things I took from that experience was the formal training they gave me in interviewing. The UK civil service used interview boards consisting of a manager of the role, a subject matter expert and an independent person from outside the organisation. It is an inherently high-stress situation for the candidate due to the numbers involved and and usually due to the room layout. I was trained to account for the stress reactions and see past a freeze due to the situation and focus on clear demonstrations of skill and experience. If anything we were trained to try to make the candidates perform at their best in the board rather than probe to see their worst sides. It was complicated by the fact I was employed in a highly technical specialist team (It was a military research agency) and few people we interviewed had any experience of what we were planning to employ them for. We also consciously went beyond a general knowledge test and focused on how the candidate thought about answering questions rather than if they knew every technical detail. In that role technical detail was only a man page or a conversation with a colleague away if you know what you didn't know and were prepared to ask for help. Any interview that stresses the candidate, quizzes the candidates memory of detailed technical facts and doesn't work from the premise that it is a high stress artificial situation is not going to provide a valuable outcome for anyone involved. Edit: My best question to identify general technical competence starts with "Can you describe the TCP handshake?" and if they know is quickly followed up with "Why is it like that?". Unless there is role specific reasons to know TCP then it doesn't really matter if they don't know, if they do know I am really interested in their answer to why it is the way it is. Many even quite senior candidates have never considered it before and watching their process of thinking about it is very instructive about their ability to think about technical details in the abstract.