What do you use to catch silent failures — cron jobs, SSL, DNS?

Hey all — launching Wakeful on PH next Tuesday (Aug 18), but wanted to start a conversation here first rather than just drop a link.

Curious how people currently catch these kinds of silent failures: a cron job stops running and nobody notices for days, an SSL cert expires over a weekend, a DNS record changes and breaks something downstream. I've been burned by all three on my own side projects — the fix each time took 5 minutes, but I had zero visibility that anything was wrong until it was already a problem.

Most monitoring tools I found either only do HTTP uptime pings, or bundle in a lot of stuff (status pages, synthetic browser tests, incident management) at a price that didn't make sense for solo/small projects. So I built Wakeful to just do four things well: cron heartbeat monitoring, SSL expiry alerts, DNS change detection, and HTTP checks — alerts to email, Discord, Telegram, or webhook.

What's your current setup for this kind of monitoring? Just cron logs and hoping for the best, or something more structured? Would love to hear what's worked (or hasn't) for you before I launch.