Interview people for your teams is not easy thing, specially when you want to enroll someone to your company and is an experience professional.
At the end of the day, everything is related to the needs of both sides of the negotiation, but there are so many areas you need to cover in your interview to sell your organization and really make the people think about a real change.
On the other hand you have to balance the tone of the interview between the fact that you need to persuade the person to engage your company and ensure it is the right person with the attitude and required knowledge.
Other aspect of the interview is the technical side of the discussion. This is performed by a subject matter expert, but I like to ask the SME about five to ten technical questions that I use to use for understanding how interviewed explains them, how s/he expresses him/her self about these topics.
An interview is always a transaction, for me is a way to know a company or a person. I always learn something talking into the interviews.