How can I break the circle?

As a web dev with no interest in front end UI, but forced to do because of current company needs and need to pay rent, what would be a way to get out of this area and focus on back end? I would prefer not to apply for a new job, but work on something in parallel in order to get more confident in another field. Would open source involvement play a role, and if yes what’s a good way of finding one? Cheers.