It would be nice if we could queue up a task to run when a job fails on its 10th retry (or last depending on retry settings)
So instead of monitoring for specific job type in a job filter (http://stackoverflow.com/questions/33703661/how-do-i-execute-a-new-job-on-success-or-failure-of-hangfire-job) you could assign a method to run upon final failure.
We have some jobs we queue up during a work flow event, however if a critical part fails we roll back the item to a different status and notify some parties. Its easy enough to try/catch log/notify on each failure within job and then throw the exception so HangFire retries but it gets much messier to catch the error on last job try and take action. I suppose another option on this would be to get a jobstate passed into a job where we could check something like IsFinalTry