Process -
A full day consisting of a test followed by several interviews and a personnel interview.
Test & most of the interviews went very well, but 1 or 2 questions came up during the day that I couldn't answer and I was not made an offer.
Advice -
1) Know *your* stuff. They will grill you in the general areas and you need to provide accurate answers.
2) Know *their* stuff or be prepared to defend your boundaries. They will also expect you to be expert in the job you are applying for. Either make sure you have all the answers or, where that's not possible, do not be afraid to say that some areas will doubtless be new to you and you are not yet at their level in those areas.