* Negotiate shorter workweek at your current job. Many people have successfully done this to reduce workweek.
* Become a consultant or contractor. If you do it right (and that's hard!) you can work shorter workweek. Or you can do OK and work shorter workweek and make less money.
* Negotiate shorter workweek at new job. This is much harder, but doable.
In my case, I was a consultant, got part time job with one of my consulting clients, then negotiated short workweek at new job. First two (consulting, first job) were <30 hours a week (when I started, at least), second job was 35 hour workweek.
(Also, every once in a while I've seen part time jobs advertised.)
Talk a bit more about this here (https://codewithoutrules.com/saneworkweek/), and a lot more in book which will be available as soon as I write the sales page (sign up at that page to hear about it).