Actually, you're not limited to specific stacks on Heroku. There are a number of options.

You can use our officially supported languages: https://devcenter.heroku.com/articles/buildpacks#officially-...

You can create a Docker image and deploy it via our container registry: https://devcenter.heroku.com/articles/container-registry-and...

You can create your own buildpack: https://devcenter.heroku.com/articles/buildpacks#creating-a-...

Or use a buildpack created by the community: https://elements.heroku.com/buildpacks

Hey jbryum, thanks for clarifying.