I'm trying to do a PhD part time while working although I don't plan to go to academia, now or in the future.

For me it's a way of focusing on some topic related to my work: I'm a machine learning engineer and I'm doing the PhD in AI/optimization. I have spent just a year on it so success is still far away.

I know people however that went back to academia but they had some previous experience for example as teaching assistants.