DevOps CI/CD/CD for Elixir/Phoenix best practice?

I used to dislike Jenkins as well, for pretty much the same reason (old and dated), until they recently released Blue Ocean (about 1-2 years ago). It’s no longer in the dark ages, and does CI/CD rather brilliantly. It’s free also. Check it out:
https://jenkins.io/projects/blueocean/

If you still don’t like it, Rundeck is a free alternative job runner that has a modern UI (relatively) as well. It’s not designed explicitly for ci/cd, nor look as slick as blue ocean, but it’s not as janky as old jenkins and runs very dependably. It’s easy to write tasks with form inputs and bash syntax directly in the interface. It’s my current weapon of choice as a build server (but that’s primarily because I have the setup automated - I would go with BlueOcean if I was starting from scratch)

Great question and I found everyone’s answers very helpful as I’m a sys-admin new to the Erlang koolaid.