I can't see MS having tens of thousands of developers working on any single component of Windows, so I'm guessing they _do_ want a giant monorepo. If they were to break it up into separate repos per OS component, I doubt they'd have scaling issues (of course, breaking things up introduces coordination and dependency issues).

Instead, we decided to - as you put it - change Git to fit our needs.

In particular, if my repo is big enough, I often don't have the entire tree in memory (because I'm doing other useful things with memory and caches got evicted). core.untrackedCache makes things a little better, but it's still not great.

GVFS is part of our effort within the company to standardize on a single set of best-of-breed tools, and use the same tools inside Microsoft that we deliver to customers. So we're adopting one engineering system throughout the company and we're moving everybody to Visual Studio Team Services.

As they say in: https://blogs.msdn.microsoft.com/bharry/2017/02/03/scaling-g...

The first big debate was – how many repos do you have – one for the whole company at one extreme or one for each small component? A big spectrum. Git is proven to work extremely well for a very large number of modest repos so we spent a bunch of time exploring what it would take to factor our large codebases into lots of tenable repos. Hmm. Ever worked in a huge code base for 20 years? Ever tried to go back afterwards and decompose it into small repos? You can guess what we discovered. The code is very hard to decompose. The cost would be very high. The risk from that level of churn would be enormous. And, we really do have scenarios where a single engineer needs to make sweeping changes across a very large swath of code. Trying to coordinate that across hundreds of repos would be very problematic.

I can't see it being desirable either, they already have to deal with outdated external API, surely they don't want outdated internal API. A single repository lets you replace an API throughout the codebase at once and remove the old one entirely, if you start "modularising" then all "internal API" are suddenly external with all that entails.

This is totally armchair-devops, but it sounds like a more ideal case would be CI that runs based on your commit. In my experience, developers get lazy and are likely to commit binaries that dont match the code or miss some dependencies or steps.

I completely agree with your point, using the tools as intended isn't always the best way to get things done. Video games are an easy example, code is often dependent and intermixed with binary assets and you want those to be versioned together.

For games the binary data isn't from code. They're textures and models generated in a package (like Photoshop). The bits of code are often tightly coupled with the textures--like a procedural waterfall that uses still images. You'd need to version both of those together.

But for the product we were building, it was important that developers were able to test their .debs before committing to the repo. That means that CI can't build post-commit: you have to have some way to take a local modification, turn it into a .deb, test it and see if it does what you want, and then commit that.

I've thrown something together for my current job that supports both building a package interactively for testing and building one in the CI pipeline post-commit (using a git repo as the source in both cases) but it's definitely more cumbersome, and I haven't figured out quite how I want to fix it.

(Also, yes, games are a more obvious example of this, but there are lots of purists who've never worked in game development who are somehow convinced that assets aren't code and shouldn't be in the code repo. Having not worked in game development myself either, I figured it was safer not to invite that argument.)

The commit is merged only after a developer will give +2 for the review.