Tip of my hat to Jeff's answer.

I will add my perspective in more of a 'big picture' way.

The biggest frustration people have in hiring - be it local, regional or international - is getting it 'right'.

'Right' is defined as the right person, at the right time, for the right job.

So in other words, whatever question(s) you ask, each must lead back to this Right Fit principle.

A caveat is to be prepared that you, for whatever reason, do not find the 'perfect' candidate (if there is such a thing).
What will you do then?

Line out your wants, must-have's and wish list of attributes. Make these clear to applicants for it to be fair play.

Last thought - know that introverts may 'bomb' the interview because of the communication situation, and not because of their worthiness. Use both written and verbal responses to judge best candidate.

Let's get on a call and get you the right hire!