[willemmerson]

You might be right about scale, but web servers already handle huge amounts of websockets, and already have complicated pub/sub schemes - think about a chat room for instance. I am using Django Channels which lets you define groups that other channels can subscribe to, and I'm sure other web frameworks have similar things. It seems easier to use than MQTT topics because it's all there right inside your webapp and DB, not on a seperate MQTT broker, this is the main thing that's attracting me to the idea.