The Codility challenge included 2 problems to be done in 3 hours. While the first one focused on performance the second one focused on correctness. I think I did both of them near perfect. Most questions in the onsite (5 rounds) were simple and decent and if not of common sense (considering the role). Some went very deep into the Linux internals but nothing unreasonable (fork, execv, tlb, etc). Other questions were related to TCP/UDP/DHCP but quite trivial. The coding challenge was about implementing a hash using C++ templates and additional things were added to the problem as I solved it. It truly seems now to me the interviewer was trying to fail me or set the bar at an unreasonable level (for the position).
