Letting non-programmers vibe-code features into a large existing product destroys its architecture, even when every individual change looks defensible.

And we ended up with a lot of PRs that individually perhaps could have been justified for a hot moment, taken all together, destroyed the architecture of the system. And we actually had to clean up manually, mop it up by hand, by human hand, to get back to an architecture that felt cohesive and coherent.