The state object is just a regular JavaScript object. I prefer to avoid classes as they increase complexity for almost no substantive benefit.

Changes to the UI are handled as events whether those events are from user interactions, HTTP responses, or web socket data events.

I update the DOM using old school DOM methods and some custom DOM methods I have written to do things the standards do not provide.

This stuff that people cry tears of blood over is easy and very basic. I really think the bane of evil is addEventListener allowing multiple handlers for the same events which allows laziness and super increased complexity.

What’s more challenging is writing test automation that executes in the browser and coordinates between browsers of different computers.