I'd to love to hear more about how you identified UX issues from pure logging data. Do y'all write anything up about this online anywhere?
But one example of how we use logging info to clean up our UX was just kind of "watching" what the users were doing by just following absurd amounts of logging (logs like "clicked x button" are short and cheap, as long as you can filter them out when needed, they are immensely valuable). Our application does a lot of barcode scanning, and we noticed just from browsing around individual paths in our log-shipping system that if some users had an error with the camera (lowend android cameras are a lot buggier than i would have imagined!), they would go into the settings, select the option to change the scanner to a wireless laser attachment, then change it back to the camera version before going back to what they were doing.
Overall the process took them a good 15-20 seconds, and when they should be scanning about 1 carton a second in the app, that added up in both time wasted and in user frustration. We added a "retry" button to the error screen, and instantly the long workaround stopped happening. Then we took it a step further and would attempt to re-grab the camera in the background before showing the error to the users, which cut down on the number of those dialogs significantly.
It was a matter of getting an alert that this "camera not readable" error was happening commonly enough to trigger an alert, and from there was about 10 minutes of browsing the "breadcrumbs" for a few users to see the pattern, maybe an hour of adding the "retry" button in the dialog box (and testing), and another hour to do the auto-retry a few days later.
3 hours of work when it's all said and done (of course, after the timesink of developing it all), and the product is better off. And that's something that i'm almost 100% confident that we would have never found out about without this kind of logging and reporting.
We use sentry.io [0] for a lot of this error logging, and we have found it incredible at being able to "walk in the user's shoes" for things like this.
I have been pushing hard for our team to implement sentry.
I have implemented JS logging for all of our AJAX interactions, but having sentry 'coalesce' everything into a single view, as you know, is immensely useful and actionable.
For us the process started with just including the script and getting a few crashes or exceptions here and there, and once most of us were comfortable that some time investment here would pay off, we really wired it in and the benefits just skyrocketed.
Now we even have it running on our server side code in one case because it's just such a damn good tool.
I will say that the downsides are that the search is fairly poor unless you self host and have access to the database, and forget about using it for any kind of reporting over time periods (it's actually really hard to see things like "number of times this error happened in the last week").
But overall it's a very easy system to layer on top of just about anything. I know nothing about your company or product, but see if you can get the approval to spend an hour or 2 to just try it out. As long as you don't have any PII its a pretty risk-free thing to try.
https://stackoverflow.com/questions/2653626/why-are-cookies-...
They have startup pricing and we've used both. It wasn't great to pay a monthly fee, but it was far cheaper than anything I could have put together myself.