[silvajoao]

Spot on. I actually know a couple of people who have been rejected and they don't have a very clear reason for the rejection.

However, I could tell during the conversation on the interviews whether I was doing well on a particular topic or not so well. I got the impression the questions just keep coming while you keep answering; when you say "I don't know this, I actually never saw similar problems before", I guess this is when the interview begins: how do you solve new problems and try to tackle them? This is also the feedback you can take away: where did you stop, and what would it take to go on?