First interview involves an exam with questions about data structures and algorithms (binary tree, strings...), and also a part about networking (tcp, udp, dns and etc.) Also questions about hash.

It was a technical test that was done manualy on a piece of paper, together with 5 other candidates in the same room. I t felt like a test in university. The exam was made of 3 algorithmic questions + a few general knowledge questions about networks.