You can create a SaaS with fully private data on the client side while using both local operations and managing control via API calls.

Think of it like a mobile app, but for the browser.

> with fully private data on the client side

How is the data fully private?

FWIW, I read that to mean "not shared with the backend".

Oh! Right, I see. I'd have thought we could do that today in Typescript or something, but maybe they have something extra in mind.

Yeah this is sort of the point. Much of JavaScripts ascendancy is simple it’s monopoly on being able to run native in browser. Wasm lets you bring other languages to the browser.

The author didn’t mention using the browsers web console or “how do I use rails console in the browser with wasm?”. That’d be interesting to me. Can I write Ruby in the web console and see things change live in my wasm app?

Outside of making something - it’s very useful for setting up a quick project.

Stackblitz did this with Node (aka their Web Containers).

You could make a new project very quickly and prototype an idea. When finished, download it off the browser and deploy it.

A common usecase for offline-first mobile app situations is shared business logic, especially for validations. Being able to validate client-side and detecting issues without a server dependency is a nice boost to UX.