Just a reminder, maybe unneeded, but… If the Ruby side is doing anything significant, the communications overhead will be trivial compared to time spent in the Ruby interpreter. Personally, I’d go for the simplest thing, whatever that is for your case.
sribe
rjk
in this context it’s also good to be aware of something like terraform. The idea would be to put your elixir app before your rails app and per route decide if you handle it with elixir or with ruby. So your elixir app is acting like a reverse proxy in front of your rails app. In this way you can gradually migrate to elixir.
Unsure if there is any authentication or other context you need to handle for the incoming requests from elixir but i’ve done stuff like this by temporarily connecting to the same database as rails (read only) or making internal api routes to get context with from elixir to rails.
Another option is going with a persistent phoenix channel connection from ruby to the elixir app but this would introduce way more complexity (and needs clear interfaces on all sides). Then I would prefer the simplest solution of terraform: handle it with elixir first (via plain HTTP) or else fallback with rails (via plain HTTP).
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