layer in some cases you can of the show some on the shelf solution where it is a black box you only have the API provided by the solution no one is telling you ok in the transformation let's replace it you purchased if you want to have return of investment over it and basically you should use it but you don't want to use first API that is going second API that is calling this code safety I try to consume it directly and then use rule engine to apply any rules that you have over data to provide domain-driven the main data that these