Of course, it’s a software pattern. The phrase “delivery mechanism” used by Uncle Bob meant to classify it as a pattern for serving content, here’s is a quote from the origin peppers 1975: “A controller is a link between a user and the system”

Given a robust backend that constitutes many business rules + 1 relational db layer + 1 search DB layer +cache access logic + interaction with other Microservices, could it not result in too fat and un-maintainable controller and model?