I bit and got the book, hoping for something interesting. It’s more or less the documentation on MDN or a WS library docs rephrased.

Finally, after 60 pages of docs I can Google, there’s a section called “Scaling Websockets”, which is an interesting and challenging topic.

Turns out it’s one paragraph long, saying - “Yeah it’s hard. You should consider using Ably. Next book will cover it.”

Shameful.