Current solution for ensuring crawlability?

What’s the currently recommended way of ensuring that Meteor applications are crawlable? I’m currently using the lufrai:spiderable2 package, which appears to work locally. However, when I deploy to a Docker environment, there’s no response when accessing the site as a crawler. I have no way of seeing why the app is unresponsive either, as it logs nothing in response to the request, only that the nginx reverse proxy eventually says that the upstream (i.e. the Meteor app) didn’t respond.