Do you think pedophiles can be rehabilitated? (Trigger warning)

After finding out the horrible truth of my SO's friend it got us on a hard discussion. Is the purpose of jail to punish or rehabilitate? If it's to rehabilitate, can a pedophile even be rehabilitated? His friend got 8 years. But I imagine in 8 years what will actually change? I'm sure this has been discussed before here but I couldn't find previous posts. I see the crime as unforgivable and impossible to rehabilitate from but I was curious as to what others thought. Can pedophiles/molesters be "fixed"?