Since beginning of time mankind has been looking for a way to separate right from wrong. Where the primeval man judged righteousness by the contributions of the tribe, the current day programmer judges right by the wishes of the customer. For many years the average programmer wrote a bunch of logic to check if the boundaries defined by the client where uphold. As time went on and programming languages involved, metadata could be added to enrich functions, methods, classes and the like.

Of course for Java, these metadata are called annotations. Very soon they were used for a lot of things. Surpressing warnings, managing transactions, building XML/JSON structures and injecting dependencies. And, as you might have guessed by now, validating objects by a set of specific rules. One of the most commonly used frameworks would be the Jakarta Bean Validation framework. But what if I told you the provided annotations of that framework could be very easily expanded.