I went through 3 rounds of interview. The first round was a technical one which went smooth and short. The second round was a little lengthy with the manager and it was interactive enough from either sides. Third round was kinda formal round with the HR regarding the salary negotiation and other benefits stuff. They took more than 2 weeks to release my offer letter and I was informed that offer letter had to go through many approvals internally. But, HR always answered my calls and replied to my emails whenever I followed up with them.