One interview, lasted from 2pm till 6.30pm, with coding sessions. The code were prime number ordering... I asked how often they calculate prime numbers in their company :) You can guess the answer. When I asked to look at the source code to check what kind of technical debt they have, they wouldn't show me. And said this was the worst code base they saw in 20 years. They're working on refactoring it. The whiteboard exercises were just weird, when you solve simple code you just use code. Still I was Changed their mind about job offer.