Your first (async/await) version was fine if that’s all that channel/topic is ever going to do - my concerns were based on the expectation that this process could accumulate more and more responsibilities over time which may not happen. I’d definitely still stick a Task.Supervisor in there and use it.
I would also hope that the actual logic behind the store and publish functions resides in (similarly named) modules separate from the channel/topic itself if only to make it easier to locate that store and publish functionality in the future (think of it as analogous to pushing functionality out of the controller into the context).
That is a consequence of using Task.await/2 to retrieve the result (which you mention).
An alternative would be to use Task.supervisor.async_stream_nolink/6 - successes are returned as :ok result tuples and crashes as :exit reason tuples. By default the stream runs as many tasks in parallel as there are schedulers online.
