There will be different levels of interview; the first one will be just for the name sake. The HR recruiter will be talking to you to know about your expectations. Do your market research and let them know your expectations. The second round will be a technical; for most of the departments, the interview will be very cool. Just keep true to whatever you have mentioned in your resume. Most of the questions will be routine textbook questions. However there are couple of teams which will be trying to grill you due to some reasons. If you apply for those teams, 'all the best'. Once you clear the tech interview, you are almost 99% IN.....

About an hour or two; mostly a combination of technical and personality fit questions: "What's your favorite language and why?"; "How do you find answers to problems?"; and so on. Not incredibly formal or high-pressure. Spoke with other developers, manager, and CIO. Transitioned to what I would call a "normal" getting-to-know-you kind of conversation after we were done with the serious questions.