Shopify's app documentation has exactly one first-class path: Node, the official CLI, and a Remix template that wires authentication for you. Pick any other language and you leave the paved road at the first turn, because everything interesting happens before your framework's router sees the request: the app runs in an iframe inside the Shopify admin, the browser will not give you a cookie there, and the token you need to call the Admin API has to be traded for on the fly. None of tha...