Not sure how opinion based my question is, but when you have a released (client facing) feature, how are you evaluating with telemetry if it's healthy? By healthy I mean users can interact with it (it's accessible) and when there was an interaction the expected outcome happened.
Here is an example for the expected outcome case:
There is a delete button and if it's pressed, a request sent to a server, and if that returns
200, the delete functionality can be assumed to work.
Let's say we are sending a metric
DeleteButtonPressed when the user presses the button and
DeleteSuccessful upon receiving the
200 response code. If there is a drop in
DeleteButtonPressed it can be said that the feature is not healthy.
However how do we know if the feature is accessible? The problem is that it cannot really be distinguished if the users are not be able to use the feature (because of let's say in a specific OS version the app behaves differently and the feature is not visible) or they don't want to interact with it. Monitoring just the rate of
DeleteButtonPressed therefore isn't a good indicator.
Maybe I'm missing something but what are good metrics to monitor feature health?