Those words have one meaning each. A microservice is a service that does only one thing, and does it simply. Something stateless doesn't keep state - after an

Those words have one meaning each. A microservice is a service that does only one thing, and does it simply. Something stateless doesn't keep state - after an interaction with a client, nothing has changed in the service itself. A stateless authentication microservice is something I would expect to run, listen on a port for some sort of authentication credentials, and return either some sort of authorizarion token or an authentication error. I don't see where the confusion comes from.