Some interactions with 3rd party libraries (like rendering stuff, leaflet.js, pixi.js) fall along natural event-driven faults, like the game update tick finishi

Some interactions with 3rd party libraries (like rendering stuff, leaflet.js, pixi.js) fall along natural event-driven faults, like the game update tick finishing, something managed by Elm being clicked, that sort of thing. In these cases, ports (events) are the obvious fit. Then there's synchronous 3rd party library stuff where you just want to execute a Javascript function, like a math function that you aren't going to reimplement in Elm. In that case, I wrap the function with a native module and call it like an Elm function. Since you talk of computation, is this what you're talking about? The Elm community highly discourages native modules. For one thing, they aren't very well documented and the API seems to have recently changed. But I'm not sure what the alternative is.