A bit lengthy and drag quite long which is quite inefficient. There are many rounds of hr interview and different technical interview which often makes me wonder is there a need to interview for at least 3-4 times.

The HR will send you the email, telling you the interview time and location. You need to be there 30 mins in advance. First round is technique interview, conducted by an expert in the relevant filed. This part lasts normally for 30 mins. Then you will meet the leader of the department you apply and have a open question talking with him.