We'll try AuthZ with Policies in a quick and dirty way, at first.

Conditions such as "if event.app == Policies then use AuthZ" are acceptable in our code. They should be hidden behind an Unleash toggle though.

Since the Policies events are related to hosts, this is a good app to start experimenting with. We'll need to forward the information about hosts from notifications-engine to ClowdApps such as notifications-recipients-resolver which will need that data to call Kessel and determine which users should receive notifications about the hosts.