@ianfeather Depending on how exotic you have gotten with your Jekyll site, I've found it a pretty straightforward journey.
@paulrobertlloyd wrote some useful thoughts on this some time ago which is still worth a read.
The fact that @eleven_ty supports Liquid helps.
https://24ways.org/2018/turn-jekyll-up-to-eleventy/
My tweets and posts live here on my own domain these days.
You can explore them here and follow me on Mastodon instead of Twitter where I'm not currently active.