I run a popular app (native ios and android) and a web version. I find having A single json serving api much easier to maintain. The frontends are isolated projects. The backend is just a simple layer with static data served as json. If you would have static html it means you need to update all static files whenever a ui change is needed. Makes it overly complicated. Caching becomes also a challenge and the so does the performance. Currently just running a few Hetzner instances to serve 50k requests per second. That would be really hard with a server side rendered html.

> If you would have static html it means you need to update all static files whenever a ui change is needed. Makes it overly complicated

We do use a templating engine and separate CSS files, so no, not at all, all static files does not need updating on every change.

> Caching becomes also a challenge and the so does the performance

Not at all, not even on black fridays.

> That would be really hard with a server side rendered html.

Why do you pose that hypothetical when our real-world experience is easy?

Do you build each interface with different tools (e.g. Swift, Java, and React), or one of the unifying tools (Flutter, React Native, etc)?

Then you're stuck with two kinds of templating.

Reminds me early AYAX days.