I found this cool post that lists some best practices when dealing with data in Elixir.
I'm not nearly as experienced with Elixir as I'm with Swift, having only played around with it for a couple of months now. However, I do find some similarities between the two languages — at least in the thinking model I use when dealing with data.
The post that I linked to talks about how you should model your data objects to be type safe. Structure your relationships, be clear about intent. Don't repeat yourself.
I don't know what it is about, but I find that both Swift and Elixir, at the language level, have pretty good ways of empowering the developer for doing this more easily.