Cognizant visited our campus.There was an aptitude conducted by Aspiring Minds(Amcat). The test was not that difficult to crack.1700 students sat for the process out of which around 1000 were shortlisted for interview. There were two interviews,technical and then HR. I think that the rank that you score in your amcat test matters because they wrote our respective ranks on our forms before giving it to the interviewer. My technical round lasted for about 15-20 minutes. I was initially asked about my favorite subjects and then were asked questions on it.Basically they ask questions on the subjects that you tell them as your favorites.I was also asked questions about the projects I had mentioned.Basically one needs to have in depth knowledge of each and every thing that you write in your resume.I cleared the technical and then gave my HR. Hr was just a formality,just a normal chat about my family background,my views on certain political issues and all.Finally cogni gave 566 offers on campus and I was one of them.So I would say for technical,have an in depth knowledge of your projects and 2 subjects that you have interest in.It is not that tough to crack,just study well and be confident.Also write those things on the resume that you have actually done,don't write things that you have no idea of.Best of luck!!!