If there’s no organizational barrier (e.g. microservices architecture, separate repos with strict permissions) that will prevent devs from leaking abstractions

If there’s no organizational barrier (e.g. microservices architecture, separate repos with strict permissions) that will prevent devs from leaking abstractions across technical boundaries, those well-defined modules and interfaces will devolve into a big ball of mud. I say this with the assumption that the team is large and members regularly come and go.