I have worked with cognizant for an year in 2 locations kolkata and chennai respectively.the work environment here is totally awesome. everything is systematic.only issue is that career growth is a bit slow compared to other it companies in the industry.job security is there as long as your personal doesn’t drop below average level.around 40% people working in cts are associated with then company for more than 7-8 yrs.in my case, I left the job to persue higher studies otherwise I was very happy working there.