I have successfully passed initial screening by a recruiter and two rounds of online interviews with different engineers. I was then invited for an onsite interview, which was held in Dublin.

The topics discussed were quite interesting as a whole, and I received mostly positive feedback. However, I failed the coding interview. I was supposed to write a piece of a well-known computer game, and I chose to do it in C. From the interviewer's point of view, I selected somewhat non-optimal data structures for the task.

What is your favorite network protocol?