Deis mostly has open source tooling on GitHub, I would expect it to stay that way. They have delivered many community projects that made it to https://github.com/kubernetes/ and https://github.com/kubernetes-incubator.

Microsoft is aligning on Git, so it's unlikely that anything will change (and the horror stories of the past are no-longer applicable for new aqui-hires.)

Vanilla git can't handle a repo the size of Microsoft's combined codebase though; surely there must be some additional secret sauce involved?

Yup. GVFS: https://blogs.msdn.microsoft.com/visualstudioalm/2017/02/03/...

A lot of development around Azure tools is done in the open under various "groups" -- MicrosoftDx, Azure, etc -- there is no one "source repo" for all products. Even when I was at Skype, the repo for that was separate from that for S4B, etc -- I'm sure this has changed in the last few years. But, there isn't a monolithic repo.

Something like Office or Windows, well, that's outside my wheel house of knowledge.

Well I'd suggest "repo" -- the tool that goes with Gerrit, and collects many git repos into reviewable release units with a manifest. That's what Android does.

(But I'd guess that's probably enough to shoot it down as a tool for Microsoft to ever use, right there. Not rightfully, but likely in fact... maybe that's the old Microsoft though.)

There is no combined Microsoft codebase

From the cited Microsoft link:

>"the Windows codebase has over 3.5 million files and is over 270 GB in size." //

That's just Windows. There's no combined codebase akin to Google's.

TFS+git would be my guess.