I would be interested to hear what technology and techniques people are using to monitor the health of their HA setup.
To paint the picture of some of the elements of my HA setup that I already monitor or plan to....
Many people, like me, have multiple hubs involved in their setup, such as Hue or Lutron bridges, Bond hubs, etc, as well as things like raspberry pi's. Particularly in the case of things like a raspberry pi, there can be a number of different services / applications that are key to the HA setup. There is also the many devices involved in a HA system, such as lights and sensors. Add into the mix different communication requirements we make use of, including Zigbee and Z-wave networks, wi-fi and Internet connections.
In terms of solutions, I use various Community apps such as Hub Information, Device Watchdog, Web and device ping apps, presence apps, Linux scripts, dashboards for display and RM rules assist with some detection and notifications. I'll post some more details in later posts.
I let my wife discover when there is an issue, then I fix it.
I use a custom battery instance in HSM, Device Activity Check , and Dashboards. Nothing monitoring my Pi's yet. Same for Bond, Lutron, and Hue hubs. Might look at a simple ping script to monitor those.
I use a combination of the HTTP Presence Sensor Driver and Web Pinger for these, then use Device Watchdog to keep an eye on things and output the result to a dashboard. EDIT - Forgot to include Hubitat Ping as well. Web Pinger gives me the Internet status, Hubitat Ping provides the status for devices such as my raspberry pi and other hubs.
Apart from my own work on this recently in my own setup, inspiration for this post came from this youtube clip. I don't necessarily implement things in the same way, but do agree with many of the principles covered.