The post compares two cloud pubsub services: Azure Web PubSub and Ably in terms of ease of development, creating a collaborative multi-user pixelart drawing app with both services.
Conclusions: Both Azure Web PubSub and Ably offer a similar pubsub feature set, but the Ably API was easier to use (although comes with the disclaimer that the author has used Ably more in the past).
Being able to publish named events and subscribe to them (client-side) without the need of handling them via an upstream server and custom event handlers was an advantage, while a potential downside is the use of a third party library increases the download size of the app.