Basically I have a composite service layer on top of backend services. The composite layer serves the fronts by simplifying queries etc... The idea has been to keep application logic out of the composite layer as much as possible. However, as usually is the case, for complicated (business) reasons I have to include some business rules to my service layer, E.g.:
minimum_subscription_length_for_product_X=5_days
What is the up-to-date way of letting the business people CRUD simple rules in a simple java application? I don't want to include a software engineer in the rule maintenance process but don't want to spend tons of money on fancy GUIs either. What is the up-to-date lightweight compromise?