A similar effort was made by Microsoft a while back to scale up Git in order to use with the Windows monorepo: https://devblogs.microsoft.com/bharry/the-largest-git-repo-o...

Junior engineer here, so got isn’t used for the windows repo? I assumed git was the holy tool or all version control.

git was created in 2005. No idea what MS uses, though some history is here: https://en.wikipedia.org/wiki/Microsoft_Visual_SourceSafe#Mi...

Microsoft used their own fork of Perforce for a long time. Not sure what they use today.

Source Depot is what it was called. IIRC, Windows was moving to Git (through some virtual file system [0]) and had some major teams actively using it, but that was a while ago too.

[0] https://github.com/microsoft/VFSForGit