This looks pretty cool! Is it basically Dokku with a web interface?
Also a Dokku fan. I don't think this project is related or uses it under the hood ( https://github.com/coollabsio/coolify/search?q=dokku ), although it's clearly similar. The marketing page only mentions Node.js support, but the Readme mentions using Buildpacks (https://github.com/coollabsio/coolify ) although it still isn't clear if it supports languages other than Node JavaScript. I would assume though if the goal is to support buildpacks and be a true Heroku replacement it will soon support everything just like Dokku.
Definitely very cool and something to keep an eye on as it develops!