This is how you would do it using Pro-Version:
https://www.jobrunr.io/en/documentation/pro/results/
I assume in the free version you would simply have your own database table where you store your results.

You could use something like .continueWith() (https://www.jobrunr.io/en/documentation/pro/job-chaining/) to do whatever you like after the job has finished. I think this might also only be a pro feature though and you might have to implement something yourself to execute code after the job has finished.