For database ingress, I use schemas, and put in aggressive validations in the changesets. For jsonb values, I use embedded_schemas (https://thoughtbot.com/blog/embedding-elixir-structs-in-ecto...), and cast their creation as a normal part of filling in the database object. For egress to a third party that accepts JSON, I use naked embedded_schemas (even better if they can be shared with the database) and use a protocol to build an custom encoder that can for example send the 3rd party a deeply structured JSON from a flat struct. Due to the way protocols work in elixir, when I send it to Oauth, Oauth will (indirectly) call my protocol code.