Oracle Developer interview questions

One hour phone interview, asked some questions about the projects that I worked on. And then asked some algorithm questions, the questions is very simply. One week later, get an on-site interview. the interview has 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, describe the technical details. The finial round: Questions about data structures and algorithms. Sort a linked list, improve the performance by multi-thread (suppose on a multi-core system).