Interviewing someone for your company is not an easy job. Sometimes you have to do it without any training. If you're lucky, in the first few interviews you will join someone experienced who will lead the interview. If you take your job seriously, you might want to read some tips and guidelines on how to conduct a great interview.
After conducting hundreds of interviews, for various positions (Researchers, Developers, Team leaders and QA engineers), I collected the 5 most important tips, in my opinion, which might help you for any kind of interview.

1. Ask "Can you give me an example?"

When the interviewee is saying something like "I was in charge of testing feature X", or "I developed many features", always ask him to give concrete examples. You will be amazed how people can talk with extreme confidence about things they did in a very general way, but once you ask them to give examples - you'll find out they don't really understand what they did.

2. Ask "What was your role in that project"?

This is quite similar to the previous tip. Candidates sometimes describe really big projects, which seem impressive. In those cases, it's important to check what they actually did on that project. More often than not, you'll find out that the role the candidate had in the project is smaller than it seemed at first.

3. Try to make the candidate talk while he is thinking

The number 1 tip that I give to candidates is to always talk while you think. In this way, the interviewer can understand better your thinking processes and might help you if you are not in the correct direction. From the interviewer perspective, many candidates don't follow that tip, and it is hard to know what they think. Simply ask them to talk and explain what they are thinking about. Even if they have ideas that they think are "bad", ask them to explain them. Sometimes they hit the correct solution to the question, but just don't say it to you since they think that there's some mistake in it. As an interviewer, you want to know that they found the solution, even if they didn't think it is correct.

4. Ask "Can you explain me an interesting bug that you encountered?"

This is my favorite interview question. It gives you an opportunity to see how good the candidate can explain something technical, and how deep he understands technical issues. It also helps you to see if the candidate can identify what was important and what wasn't.

5. Don't have small-talks with your co-interviewer

The interviewee is under a lot of stress and is trying to think. Yes, you might be bored, and yes, it is much more interesting to talk about what to eat for lunch than look at someone you don't know trying to solve a question you know. But you should respect the candidate, and you shouldn't disturb him

What do you think about the tips in this article? Do you have any other tips for someone who begins to interview? Let me know if the article was useful to someone.