It’s really hard. And really expensive. I used to work in five nine environments, life or death type use cases, and my rule of thumb was that you double your cost for every extra nine you add.
When we got to five nines it was multiple hot standbys with a custom control and orchestration plane - literally custom hardware we had to build. This was for local installations, so not modern cloud environments (it was over a decade ago), but many of the challenges are similar, like session handling, transmission replay and caching, locking, clashing, routing, jitter, latency etc.
Homepage is great. I like that you get little snippets from the apps it links through but is more customisable than something like Heimdall which does similar. It’s become my go-to having tried pretty much every other dashboard out there over the years.