Most of the time you know nothing about the interview until someone asks you to give them a technical screening an hour before. There is also no formal process or seeming involvement from HR, it's just a, "is this person any good". From my experience it often comes down to, in order of importance: - Are they willing to be perm - Do they know what they are talking about - Will they fit in the team
The first one seems to be a trump card, even though most perms end up leaving before the contractors.
This brings me onto another point in which the best interview process is hiring someone as a consultant, and then converting them after a year or so if you are both happy to.