Precompiled headers eliminate some of these issues, if the usage is right. At one of my former companies any available build optimization stuff had been added to the code base over the years by the DevOps guys without any thought about how the thing would work together, and it just got slower and slower. At the end, the initial 5-minute complete build time increased to about 35 minutes, of which about 10 minutes could be attributed to the various refactors and extremely high amount of templating, but couldn't find a cause for the extra 20-minute increase. It was about 15 minutes to test just a single change.