Not understanding SQL (and in some cases NoSQL DBs) and the underlying database are a reason that so many full stack devs suck. Just because they use an ORM, they think the database work is magically solved, until they realize it’s just doing what they’re telling it to do and their lack of DB understanding has created an awful database structure. And then a DBA comes in, and then the entire ORM layer has to be scrapped because it’s trash, so on and so forth. A full stack engineer doesn’t have to be a DBA, but they sure as hell need to know what the ORM is doing to their data they are CRUDing