The Examination Process is as follows:
1. Take the exam
2. Submit a qualification form
3. Interview with a two-person panel.
You have to pass each step to proceed to the next. Once you have passed all steps, you receive a Band letter. They typically only pull from Bands 1, 2, & maaaaybe 3.
Once you are on a reachable Band, you are interviewed at each office that is interested in you. So again, the interview that goes into your Band score is NOT the only interview.
The interviews for the exam and at the offices are pretty much the same. They are pretty formal and it's simply a question and answer session. They write the entire time that you are talking, so don't expect to get much emotion from your interviewers.