It's also interesting to note how much of Microsoft's work for handling large repos in git has merged upstream directly into git itself.

One very interesting part of that is the effort that has gone into the git commit-graph: https://git-scm.com/docs/commit-graph.

It's part of what makes scalar interesting compared to some of the projects you hear mentioned used inside the FB and Google gates: not only is scalar itself open source, but a lot of what scalar does is tune configuration flags to turn on optional git features such as the commit-graph, sparse checkout "cones", etc that are all themselves directly supported by the git client. Even if you aren't at the scale where it makes sense to use all of the tools that scalar provides, you can get some interesting baby steps by following scalar's "advice" on git configuration.