Well, this made me realize that downforeveryoneorjustme.com is useless, because HN was down from multiple servers, but dfeojm happily claimed it was up, only later changed it to down, not sure when, but at least 10 minutes after it started.
Though, for pure power, I prefer https://jsdelivr.com/globalping to do an HTTP ping, easily check from like 100 different locations worldwide live. It also does a great job at helping you know if it's just slow in your area or worldwide or whatever.