Agreed. When a company outgrows its monolith this component you describe is normally the hardest part to figure out. All those sneaky little joins and stored pr

Agreed. When a company outgrows its monolith this component you describe is normally the hardest part to figure out. All those sneaky little joins and stored procedures and undocumented use cases come pouring out. If your data layer has an API from the start it makes everyone act honestly about data access and provides more accountability. An API layer also allows for more options when dealing with caching, noisy neighbors, retention, consistency, and security.