The first contact was through a recruiter, but for a position that was actually advertised on the company website. It took a little while to get an interview arranged.
The first interview consisted in a 1:1 interview with 2 peers (same job, some seniority - director in this case). This was relatively standard: talk about my experience, discuss the job, the company, the current state of the business, etc. Nothing frightening or too technical, but the questions were quite precise.
The conclusion of this first interview: "We'll definitely call you in for another interview".
Then came the wait.... 4 weeks at least.
I was then invited to another interview, but for potentially another job (or not? I will never know), with someone unfamiliar to the recruiter. So I Basically, I was flying blind.
The tone of the interview was totally different. The interviewer was more senior, and involved in a totally different team. Clearly, he had formed an opinion based on my CV only, and is mantra was "you won't like it here, it's a big company". Funny that, considering he joined UBS less than a year before, also from a much smaller company. He kept complaining about the size of the place, etc.
Needless to say, his verdict, which came a few days after the interview, was that I would not fit in such a big company.
Apparently, this is the way UBS operate: make you meet loads of people in various teams. I guess it takes a bit of luck to avoid the grumpy old guy who regrets moving there.