[zelphirkalt]

With an appropriately configured CI pipeline, submitted / pushed code does not go live anyway, unless all tests and other checks pass. Unless a test case is missing, which can happen in a mono repo just as well, the code is always checked for the defect.

[humanrebar]

It's impossible to test for every kind of regression. Concurrency and performance bugs are notoriously problematic. At the scales of large codebases, you can have very thorough tests, but they need to be reasonably fast and behave the same way every time they run.

[zelphirkalt]

True, but those notoriously hard to find bugs are still notoriously hard to ind in a monorepo as well. I don't see anything in the character of a monorepo, that would somehow enable me to find concurrency bugs in an easier way than in a non-monorepo setting.