99% of our rollbar exceptions right now are ActionController::RoutingError exceptions (e.g 404/not found requests).
These exceptions could happen for a number of reasons, like users entering the wrong URL by mistake or perhaps nefarious reasons (e.g. we are getting traffic to /wp-login). But sometimes they can happen for legit reasons, like we have a bad link in our application, or we are telling uses to download an asset that doesn't exist.
We should first investigate some of the most common ActionController::RoutingError exceptions and see if we can fix a few of them.
But ultimately we may want to just ignore these errors in Rollbar like we did for Jupiter: https://github.com/ualbertalib/jupiter/blob/master/config/initializers/rollbar.rb#L34
Link to exceptions in Rollbar: https://app.rollbar.com/a/ualbertalib/fix/item/library-cms/7