Campus interview is main source of recruitement. First round of campus is a written test similar to Management Entrance test but with some technical questions also.once you clear written test (Normal clearing score is 70%) then there is a workshop/discussion where you get a task along with a nominated team and you have to solve the task with the team. The task is normally a trick task where they look for certain soft skills, people management and leadership qualities. Once you clear both of these then there is a technical interview round (after gap of 2-3 days) where they will check your sharpness as well as some of management skills. Once you clear this then you are almost 90% sure to get through. The last round is offer interview, where the top management person or panel of top management interviews you. On succesfully clearing this you get an offer, which you should read and sign then only. thats is how the process works for campus recruitment.