[tnolet]

We do synthetics and heartbeat monitoring for quite some companies (link in bio) but this problem is a bit trickier, or let's say "three sided"

1. Yes, a synthetic check is very useful here to just see if a user facing "thing" is still working.

2. a heartbeat check / deadman's switch can also work here, but it will only be reliable when the monitored event has a predefined cadence, e.g. "every 5 minutes this should happen".

3. The lack / absence of metrics flowing into a system is also sign. This would typically be solved by the Signoz team where they would alert on not seeing some specific event happening for x time. This can be tricky if the event is directly related to a user interaction.

Super big disclaimer: founder at a monitoring company that solve 1 and 2, not 3.