So they develop this app. That uses our front end component library. That queries a GraphQL layer developed as NPM package. That uses a data service abstraction NPM package. That uses another NPM package mapper library. That queries an old REST API returning XML.

It takes days to make a newly added XML node in the bottom-most layer available in the app, requiring changes to 4 repositories and 3 NPM releases.
Refactoring is dead, because 1 change will affect all layers. And the worst part is: theres only 1 app using these packages, so no case for re-use. Overzealous separation of concerns I guess?