hello! I am trying to release a shadow-cljs app through heroku. does anyone know of any guides that can help me get through this process? I haven't ever done this before.

You mean that you advanced compiled an app, and now you want to publish it?

https://blog.heroku.com/deploying-react-with-zero-configuration

should be straightforward but I've never used it either

yeah I've run the release command on my application so now I want to go through the process of publishing it. i will take a look at that link, thank you!

Question: Is it possible to run two release builds in parallel?

sure, just not with the default commands

typically you won't gain much doing it. compiltation is already parallel and should use most cores most of the time