Big companies, means lot of zombie coders which means lots of meetings which means lots of hierarchy, which again means less of coding . Smaller teams lead to better quality code and faster delivery times. Which is what i have experienced and if you want to get into the theory of this.Read " The Mythical Man-Month"
The so called TOP companies like TCS, infosys do not hire programmers they hire people
who can be "trained" to code. These people can be called zombie coders who have no purpose
and passion for coding. Their ultimate aim is to stay a programmer for five years and then move to management. And as very obvious these people will produce poor quality code
and as for the smaller companies, these are were the talent lies, because these are usually
startups and looking for additional revenue to fund their projects