Good article about large builds. I know of at least one outfit with a large legacy C++ code spend the effort to move to C#, in no small part due to unmanageable build times. This would be under the "constant reduce" leg of this journey, but with C# you cut your file count in half all other things being equal.

A minor nit: most other builds should be O(WhateverChanged) -- consider a C++ header file used by 10 c++ files. Those 10 would need to be recompiled. The agony there is that you wish for some less-than-full-file dependency analysis so that only the files that use that constant you just changed need to recompile.

On the whole a good start to those massive builds you have.