Our first rule of thumb in selecting a rules engine is normally: you don't need a rules engine. We've seen too many people tying themselves to a hard-to-test black-box rules engine for spurious reasons, when custom code would have been a better solution. That said, we've had success using Clara rules for scenarios where a rules engine does make sense. We like that it uses simple Clojure code to express and evaluate the rules, which means they are amenable to refactoring, testing and source control. Rather than chasing the illusion that business people should directly manipulate the rules, it drives collaboration between the business experts and developers.

Our first rule of thumb in selecting a rules engine is normally: you don't need a rules engine. We've seen too many people tying themselves to a hard-to-test black-box rules engine for spurious reasons, when custom code would have been a better solution. That said, we've had success using Clara rules for scenarios where a rules engine does make sense. We like that it uses simple Clojure code to express and evaluate the rules, which means they are amenable to refactoring, testing and source control. Rather than chasing the illusion that business people should directly manipulate the rules, it drives collaboration between the business experts and developers.