I applied online, got an online test, chose C. Test was not bad. Brush up C concepts. Questions on C, predicting program output, and bugs in the code. Next round was a phone interview, had UNIX based questions on processes, threads, accessing shared memory, about the pipe system call, etc. and one algorithms based question. After that, I went onsite. Had a technical interview, which I enjoyed, questions based on the internal working on C function calls, stack memory, etc. Another interview with a manager, which was personality questions plus puzzles. And a final round with HR.