Two nulls are not zero
A monitoring dashboard has three ways of not knowing something, and every one of them has been drawn as a confident zero at least once. Here is why that is the most expensive bug a status screen can have.
The Nest
HarpyWatch's writing on monitoring, uptime, and the things that break quietly.
Thirty-one checks, one grid
HarpyWatch runs thirty-one distinct kinds of check against a site — not thirty-one variations on an HTTP request. Here is the full list, what each one is actually for, and why they share a single screen.