Why hello :) Long subject and there are some things about Zanzibar that I'd build differently if I had the chance, but there are a few things I believe strongly about authz. Hmm, actually, for Random Reasons I needed to explain what Zanzibar was so I happen to have a short explainer

The explainer has both: 1) a bunch of the reasoning behind the semantics (it's the abbreviated explanation and I know I owe you and everyone the longer version) 2) a short explainer of what the system is (I know you don't need that part)