There is initially a telephone interview (around 30 minutes), after this you are invited on to sight, there is a face to face interview and a short written assessment/numerical (based on which department your applying for)

The interview process usually repeats the same questions in both of the two rounds, the first interviewer was very bubbly the second one was much more serious and stern. Overall the questions were good and as they do repeat they are checking to make sure you answer similarly.