Interview process is long and is geared towards finding people who strive to achieve more than they are capable of.
First I was asked to fill out a form, that had some simple questions. Since I answered the form satisfactorily, I passed on to the first call which basically is not an interview, but just done so that they get the reason why you applied, and what kind of learning, expactations etc do you have from the company.
If all goes well, you move on to the first and second tech round. Based on the performance, you are given a small project to do in 3-5 days.
If you are still in the process, and not screened out, you are finally called to the office for a trial period of 7-10 days. The trial period is paid for, and even your travel is reimbursed (if you are coming from some another city etc).
The trial period is basically done to gauge how well you fit in the team, as capability is already checked for in the previous rounds. If you fit well, and you like the team too, then you are in!