Leveraging Ecto custom types for richer domain structures

Primitive obsession can complicate codebases by over-relying on simple, native data types. The article introduces the concept of Ecto custom types in Elixir to handle such primitive data more effectively. By creating custom Ecto types, developers can transform simple data types into more meaningful domain-specific structures. The example provided focuses on creating a `%PhoneNumber{}` struct with custom parse and transformation functions. It details the process of defining the custom Ecto type with functions like `cast/1`, `load/1`, and `dump/1` to integrate richer data structures seamlessly into the application's database schema and Ecto changesets. Furthermore, it shows how these custom types can be used within embedded schemas for even better form handling. This approach allows a domain-driven design where the application logic deals directly with relevant domain structures, improving maintainability and clarity.