I just finished the talk, I just want to clarify one more thing regarding the compilation. Renan mentioned that the Phoenix router takes a long time to compile but that’s likely not the case. The issue is that a lot of his application likely depends on the router and that holds everything else back. To some extent this is Phoenix’s fault since controllers and views import the router and that sets up a compile time dependency. I have pinged Renan to confirm this and opened up an issue on Phoenix’s issues tracker.

I would say that’s fine. The real issue is that many modules have a compile time dependency on the router and that could be solved if we aliases the router helpers instead of importing them.

This was a pretty good description of real world Phoenix. I enjoy hearing what worked and didn’t for other groups.

Just wanted to add that It’s pretty easy to introduce a lot of module dependencies to the router via plugs, e.g.:

# router.ex
plug MyApp.CurrentUser

# current_user.ex
def call(conn, _) do
  Users.get(...)
end

this introduces a compile-time dependency between the Router and MyApp.CurrentUser
And then if the Users/User modules (or any of their runtime/compile dependencies) change the router will need to be recompiled and thus all controllers & views. Although it’s a hacky solution, having one Module.concat in critical place (e.g. the one plug that reaches out to schemas) can save a lot of recompilations.