One hour phone interview. I was asked some questions about the projects I worked on. Then, some algorithm questions were asked; the questions were very simple. One week later, I got an on-site interview. The interview had 3 rounds:

The first round: Questions related to OS, Kernel, etc.

The second round: Questions about the projects I have worked on, like which one is your favorite and why, and describe the technical details.

The final round: Questions about data structures and algorithms. Sort a linked list, improve performance using multi-threading (suppose on a multi-core system).

Questions about the OS and kernel.

How an I/O request is processed by the system, from user mode to kernel mode.

Sort a linked list, improve the performance by multi-threading on a multi-core system.