Software Architecture

  Problem to solve: We create a core software entity, for example a  Product  - this will become  root  or  parent  entity Then we create multiple "child" entities that depend on  Product . For example  Order  and  Warranty . We have business rules for the "parent" entity that depend on "child" entities. For example you cannot remove a  Product  if there are in-flight  Orders;  or if the  Warranty  period is not over for all the instances of that  Product We want to avoid putting all those business rules in  Product , because such "tight coupling" would make the software harder to maintain as the system grows. Solution: TLDR: It helps to imagine the entities  Product ,  Order  and  Warranty  as defined in separate software modules, either in a modular monolith or in a microservice architecture. This will highlight the loose coupling we want to achieve. Howeve...