>> where I happened to talk to a guy between written test sessions who even had taken very elaborate 'class notes' on clearing these interviews.

Pretty sure there would be coaching classes to get into coaching classes with higher hit rates of finally clearing the interviews. It's that broken.

Whenever people talk about the madness of India's youth, I can't help not quoting Soumen:

"It's hard to overstress the liability of a nation of a billion people out of which 700 million are functionally illiterate and the rest have no wish to follow instructions, even when they are asking for a favor."

http://www.cse.iitb.ac.in/soumen/APKGKAH/illiterate/Applicat...

>> As a side note, in all major IT services companies in India you have to take 'certification exams' for pay hikes and promotions.

Hope you are fortunate enough to be not working for such places anymore.