> In a versioned world, you can still freeze your dependency at 1.324.5234, and migrate only when you want to, and when you're feeling confident about it.

The correct course of action is to either reverse/fix the code change to the library you depend on, or if your code is clearly using the library wrong and can be easily fixed, to do that. Not to let the whole ecosystem slowly spiral out of control.

Either way, the point is that it will force the issue to be resolved, quickly, and the code base to move forward.

The tools/libraries you depend on are themselves dependent on other libraries and tools. They may have done changes that are necessary to continue working, which you are not picking up if you stay behind. They will do IPC and RPC and always rely on their infrastructure being current.

>In a monorepo world, you don't have a choice. You've been forcefully migrated

Yes, and that's good, because:

> and migrate only when you want to, and when you're feeling confident about it.

... does not help in moving the code forward.

If your change will break others, you need to coordinate with those others so that the transition happens gracefully, not let them live on what amounts to unsupported (and slowly more incompatible) code.

> The next morning, all your services end up broken as a result.

I mean, this is the argument for having good integration tests.

At some point someone has to figure out if the new code will break a system; if you don't have good integration tests you're basically left eyeballing the changes, and sure eyeballing changes can work fine in small teams, but at some point you need good tests.

I did some work on a ranking system last year, and by definition there's no way to roll that out incrementally, because, well, it is the central component deciding what thing to do/show, and you have to change the world at once, there is literally no other option. So you need good ways of evaluating these wide reaching changes.

"If you liked it then you shoulda put a test on it" :)

> Like you said, their intent is just to add a new option, and it ought to have no extensional changes in behavior, but it still ends up behaving subtly different. The next morning, all your services end up broken as a result.

Someone makes a commit to library code and production magically breaks? How does that happen?