Three unrelated things kept breaking the same way: a cron job's entry gets silently dropped in a server migration, a Let's Encrypt renewal hook fails quietly, or a domain bought years ago for a side project expires and takes a live site down with it. Nobody notices until a client does.
So I built Keepalive, one dashboard that watches all three:
Cron jobs: each one gets a unique check-in URL to call on success. Miss the expected schedule, get an alert.
SSL certificates: checked on a schedule, flagged before they expire, not after.
Domain registration: same idea, via WHOIS.
