This applies to performance optimizations which leave the interface untouched, but there are other scenarios, for example: - Performance optimizations which ca

This applies to performance optimizations which leave the interface untouched, but there are other scenarios, for example: - Performance optimizations which can't be realized without changing the interface model. For example, FOO_TABLE should actually be BAR and BAZ with different update patterns to allow for efficient caching and querying. - Domain model updates, adding/updating/removing new properties or entities. This kind of update will still require the 32 consumers to upgrade. The API-based approach has benefits in terms of the migration process and backwards-compatibility though (a HTTP API is much easier to version than a DB schema, although you can also do this on the DB level by only allowing queries on views).