Google

It is basically testing your ability and knowledge about real-life projects and algorithms. It is very hard if you don't prepare enough for it. You should spend at least a few months preparing for the interview.

This interview process is pretty straightforward and standard. You can find everything about it online. Coding interviews require some algorithm knowledge. Basic dynamic programming and some graph knowledge would be sufficient. The system design in

There are two rounds of phone interviews plus an onsite interview. They also provide an interview training session. The onsite interview has five interviewers and one person to have lunch with you.