The author is generally right. But it's not unique to compilers. Many things were often written by just one person in the early days, but rarely so now. PC a

The author is generally right. But it's not unique to compilers. Many things were often written by just one person in the early days, but rarely so now. PC and console games, for example, were often written by one person. Now of course there are huge studios that do it (although mobile games can now be written by one person). Programs have seen an explosion in feature set. For compilers this feature set includes optimzation, and additionally things like AutoComplete/IntelliSense, debug information, precompiled headers, etc... With that said optimization probably dominates, in terms of headcount, what most compiler devs work on.