A bit salse-y, but Oso has a pretty nice overview on the problems that led to their product and how they reason about AuthN/AuthZ: https://www.osohq.com/academy

A bit salse-y, but Oso has a pretty nice overview on the problems that led to their product and how they reason about AuthN/AuthZ: https://www.osohq.com/academy https://www.osohq.com/academy It's more focused on application level architecture rather than the whole domain of AuthN/AuthZ, but I've found it's a decent reference for folks unfamiliar with a lot of the common issues one encounters in implementation.