Except I remember my times as sysadmin, putting out fires on Tomcats brought to their knees by 1 poorly performing query and a few impatient users hitting F5.

Except I remember my times as sysadmin, putting out fires on Tomcats brought to their knees by 1 poorly performing query and a few impatient users hitting F5. Yes, async is indeed more complex but it is a measurable improvement over previous - thread based - designs, and it is trivial to hit scenarios where it will make a difference. Just like anything though, it must be applied sensibly: not every single call must be decomposed into a choreography of async collaborators (yes, listen that, it’s “architecture talk”, it’s like that dark language used in Mordor that even Gandalf is scared to pronounce. Ever worked on a DDD/CQRS/ES project? ;)