Context: We have some features that rarely calls any backend service and the logic stays in the frontend.
Most of the tools we have can calculate SLI/SLO status based on latency and error code return from the server side, but right now since the applications is frontend-heavy, we're mostly tracking bugs based on user reports, manually.
We're trying to add some services to track the end user interaction and hope that we can collect some metrics like number of clicks for example.
The main question is: what are the good metrics to collect for a frontend application?
I think analyzing bug tickets, user feedback, and surveys are good methods also but I'm looking for some "black box" metrics so based on that we can set up some kind of alerts to notify our team to send someone to investigate before bug tickets arrive.