Includes 4 levels of discussion.
Level1: Technical Panel - Basic technical information is discussed. They seem to try to understand if i qualify or not within 10 minutes. If we cater to the expectation interview flows up to 30 minutes.
Level2: Technical discussion with Senior Technical people. Much difficult and more technical questions are asked. They try to check the depth. Need not worry. Try to answer to the depth you can. You are free to say I dont know. and is not a mistake. People try to scrutinize in the areas you say you are strong.
Level3: Managerial round: More personal, emotional, ethical questions, scenarios you will be able to see. Since its a product company, they try to make sure, if the candidate is selected, how long he would stay. You have to provide honest answers else, they are ready to reject.
Level 4: HR Round. Some emotional and technical questions. And salary discussions.