Thanks for the thoughtful replies so far! Our use case is actually spread out over a couple time scales, from sub-second to maybe 10 seconds depending on the service. This is a backend “dashboard” style app that collects information from a few different places - some of them are quick and some aren’t. The upshot is we definitely have a case for doing some of these things asynchronously I think.
I’m starting to lean towards introducing a mediator layer to handle these things and then trying to keep the “business” logic (actually calling out to the external service) on the opposite side of that layer than the view. It feels heavy-handed but I haven’t been able to come up with something more elegant (that’s why I asked here!). It’s going to be a little tricky because I don’t want that mediator layer to be a single process, which would become a bottleneck, so I’ll probably have an ETS table in front of it.
