Ecto: seeking advice for table/Schema design - multiple joint tables between two entities

[benperiton]

Sounds like you want to use polymorphism / single table inheritance - this is quite an informative thread.

How to handle schemas polymorphism in Phoenix?

Nah, Ecto tries to be as near to SQL as possible while doing some type checking and validation and such, so seeing how to do it in SQL is precisely what you want to do.