This project uses Quickshot and Compass to handle local development.
Workflow is based off this model. Instead of using the Shopify Theme Gem, we're using Quickshot instead.
In your terminal, you'll have two tabs open, one for qs theme watch and another for compass watch. Depending on where you configured Quickshot and Compass, you'll need to be in different directories to make sure you're watching the right folders.
For example, I run qs theme watch in the top level directory and run compass watch in the theme directory below that.
Using Quickshot allows us to to sync our scss files to Shopify. Using Compass allows us to compile regular scss files (with full scss functionality, not the limited Shopify way) to scss.liquid files, which Quickshot watches for and compiles to regular css. This css file is then uploaded to Shopify.
This gives us full scss functionality, and with some minor mixins + liquid escaping, we can now leverage both scss and Liquid to their fullest.