Compilation times and flakiness of bespoke build systems. Most of my time is C++ (game dev) and while we've reduced our compilation/link times with the standard

Compilation times and flakiness of bespoke build systems. Most of my time is C++ (game dev) and while we've reduced our compilation/link times with the standard tricks ("unity" files and distributed compilation) I'd still love for it to be as fast as something like C# or C for that matter. It would be cool if there was some way to build a "progressive" C++ compiler where initially the generated code was poorer quality (except perhaps along a hot path ala https://en.wikipedia.org/wiki/Profile-guided_optimization https://en.wikipedia.org/wiki/Profile-guided_optimization) and gradually refined/hot patched into a running process.