I’d say anyone wanting to go this deep into a home monitoring setup will likely go with what works best for them instead of reading and following the entirety of this guide… I’m one of those people…
Wrote my own log parsing software to put into a database, display and alert through grafana, which is alerting through a homemade webhook that sends a notification to ntfy based on severity… And I also use uptime Kuma like mentioned, but my notifications channel is ntfy. No cloudflare for my internal services, only wireguard to connect home and use everything. And definitely no telegram.
Plenty of other stuff setup, but my security alerts and monitoring rely heavily on the syslog/grafana server which helps me monitor everything.
The light flickering on stars and planets has to do with the Earth’s atmosphere. In a dark sky look straight up and the stars directly above you will blink much less, and as you look at stars closer and closer to the horizon, they start to blink more and more. The worse your overall seeing conditions are for the night, the more intense the blinking can get.