This is the distinction we make too: business validations go in the database, ux-validations go in the application. In practice, however, this means the busine

This is the distinction we make too: business validations go in the database, ux-validations go in the application. In practice, however, this means the business validations are duplicated all over the place (but always enforced, as last line of defence, in the database). It also means customers get more frequent 500 errors (exceptions): when a business rule is implemented in DB but not (yet) in an application. It is messy.