The best approach would be to publish the broadcast when the resource is available, after that one minute. What triggers the resource becoming available? Wherever that codepath is, is where you can hook in the broadcast. If it’s third-party processing, see if they support a post-back URL to your app, which you can then use to broadcast. Make sense?

??? The process which calls Task.start does not block, and I don’t see how the blocking inside of the task could possibly matter, since it’s not visible to anything.

Task.start(fn ->
  :timer.sleep(60*1000)
  PhoenixApp.Web.Endpoint.broadcast("channel_name", "xx_update", %{payload: %{id: 1} })
end)

but this is very hackish - you really want to broadcast directly when the publication is ready.. (as @chrismccord said..)