[BrandonY]

Once, I noticed that a minor piece of how Google's Python system tests could be very slightly cleaner and more consistent. It would be a tiny change, it seemed very safe, and it was easily accomplishable with a short sed script, but it'd also be a backward-incompatible change across the projects of hundreds of teams and thousands of build targets. I was able to make that change with only a few commits and without needing to bother most of those teams.

These sorts of small, general, large scale cleanup commits are quite common at Google, and they're encouraged. They help keep the codebase healthy. There are special groups that review them so that all of the individual teams affected don't have to bother, and there are tools to manage the additional testing and approval requirements for such a change.

At my previous company, making such a change would have been a major undertaking. I never would have considered a refactor of that scale without a critical need. They had thousands of packages, each of which had its own repository and an incredibly complex web of build and runtime dependencies. It was a nightmare, and fiddling to find a working sets of versions of internal dependencies took up way, way too much of my time each day.