Running untrusted JavaScript inside Elixir with WebAssembly

Author here. This started as a concept for user-written functions in Arke (https://github.com/arkemis/arke), an open-source backend-as-a-service written in Elixir. I'm not part of Arkemis, I just like contributing to their projects. It's a proof of concept and the code isn't published.

I'm posting it as a starting point for discussion. There are several ways to implement this and some look less viable than others, so I'd like to hear which ones you'd pick and where this one breaks.

The two parts I care about: a function starts with zero capabilities and only gets what's in the WIT world, and every function is a row, so on boot the node rebuilds routes, cron and triggers from the table.