We need to start by eliminating profit completely from the prison system (and also from healthcare).

Then we need to work on all the rest of it. I happen to know, for example, that many parole officers consider it a "win" when they can get somebody back into prison instead of considering it a "win" when they get a job, a house, or custody of their kids back. I wonder how much difference the simple measure of assessing them for bonuses based on the success of their clients returning to productive life would make.