Pros
Great brand name and a place to learn the industry. You get exposure to a lot of top clients working on high level, challenging projects. As a brand name, Cognizant can open a lot of doors and is highly well respected in a fast growing industry. You work with interesting, smart people from many different cultures.
Cons
Politics, lack of control for one's future, feeling out of loop and lack of organization. The feeling is that there's a lot run by the seat of the pants. The good news is that it's decentralized. The bad news is that it's decentralized and you feel as though you're on an island except when working on a team project. The company has become this way due to their tremendous business success and rapid growth, so one cannot expect to have the same "family" feel as it was years ago.