To have under/on your job a collection of stars (or other icon) to represent your prestige levels they could be outlined until you complete them, or simply not there.

They could or could not replace the +20% reward text. I personally would not replace it.

An example of a job that has 4/5 on time and 2/5 on reward. would be 6/10 little stars. Just a nice visual thing for when you look at your job page and a reminder of your status. 

This is a repost by Nexus from the Discord, all credit goes to him but it seems to have been a little forgotten even though it has 23 upvotes there.

I can't recall what my issue with this before was when trying to implement it, but I'm rolling this out to preview now and will be live later today.