Does anyone have "aha" moments to share about working in a single repository?
Stuff that just made you say, "Great, I wouldn't have been able to do that if it was in separate repositories!".
Stuff that just made you say, "Great, I wouldn't have been able to do that if it was in separate repositories!".
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.
With a fragmented large code base you're in a world of hurt because you're dealing with versioning. There is no guarantee of when every other dependency will migrate to the latest code path.
But again, if you're in a 1-10 person team working on some trivial codebase, a monorepo might not be helpful. If you have 500 engineers working on a single codebase, tradeoffs change.
[1] - https://buckbuild.com
2. Having no friction to change anything makes you far more productive and ambitious.
3. Scripting at a org-level means you can automate things more easily and more in depth.
We run an entirely node stack so Lerna enables this in the first place. Given that, I'd never move to more than one repo if possible. It's almost all downside: more overhead/fragmentation, less control, more wasted time/mental overhead moving between things, API friction that reduces ambitious change.
Only downside of monorepo is Github not supporting them well. If you want to release some sub-packages as OSS, or want to use GH to track issues you're stuck using one big repo to handle everything. I'd bet Github fixes this within the next year or so though.