Route alerts somewhere you will see them
For a solo developer, email is usually the wrong channel — it arrives alongside everything else and gets triaged tomorrow. A Discord or Telegram message reaches you in seconds and costs nothing.
Webhooks are worth the extra five minutes if you want something custom: a push notification, a home automation light, a message into whatever tool you already live in.
Watch the things that fail quietly
Side projects rarely fail loudly. A free-tier database goes to sleep after inactivity. A hosting platform suspends the app for exceeding a quota. A background job stops running because a token expired.
None of these produce an error anyone sees, because nobody is looking. A health endpoint that touches the database and a heartbeat check on your scheduled jobs cover most of it.
Keep it proportionate
A project with modest traffic does not need thirty-second checks from seven continents. Five-minute checks from a couple of regions catch essentially everything that matters at that scale, without generating noise you will start ignoring.
The goal is to know within a reasonable window, not to build a NOC for a weekend project.