I’ve been having similar thoughts recently 
Elixir is introducing and making easy so many fantastic ‘best practices’ which have been slowly answering my burning curiosity of “surely there is a better way of developing???” that I frequently had when I was using Rails.
Things like easily being able to build your app as a series of components, or preferring not to use if/else’s (and multiple function defs with pattern matching instead) meaning functions do one thing 
I blogged again: “Configuring Elixir Libraries”. This extends my series on designing libraries for Elixir. So far there’s just one more post: “Error Handling in Elixir Libraries”.
If you have some suggestions on other topics I could cover there, I’m open to suggestions!
I’d be interested in reading about how to make a library reusable. As per the Ecto repository pattern where you use Ecto.Repo in your own module to allow multiple repositories in a single Elixir application. To also cover how best to supervise processes, and their naming conventions.
So there’s a few blog posts about Elixir on our blog at Blog: What's been on our mind... | AmberBit Sp. z o. o. that I wasn’t posting here and you may like:
Enjoy!
Really cool!!
Accessing priv directory
You probably have some migrations and other stuff inside /priv directory, to access it use Application.app_dir(app, [“priv”]) in your Elixir code and OTP machinery would make sure you won’t loose files inside of it.
Ugh, no!
To get the priv directory always use only :code.priv_dir(:my_app_name)! Though ‘most’ of the time priv will be in the app’s directory, it ‘could’ also be elsewhere, renamed, and variety of other things, and as such this will break in certain situations (like, say, running from inside a tar file or so)… >.>
Application.app_dir does exactly the same :code.priv_dir does minus appending of the priv part. There is no difference between them.
There is last I saw. Last I checked Application.app_dir/2 calls :code.lib_dir(:app), which returns the path to the app library directory (which might be a tar file for example, but without the extension), and then it uses Path.join/2 to append it. Where calling :code.lib_dir(:app) instead queries the :code_server directly, which then properly puts the path on to the end of the lib_path, using something similar to Path.join when it is a path, or doing something ‘else’ when it is a packaged file (like a tar file). In addition some custom BEAM builds use a priv directory located and named elsewhere for embedded systems (admittedly this was a decade ago).
Well I just wrote a summary of the Elixir.LDN conference Elixir.LDN 2017 - Dimitris Zorbas
But I think folks might also find this post about Docker multi-stage Distillery releases useful. Distillery releases with Docker multi-stage builds - Dimitris Zorbas
