The example repository RepositoriesElasticsearch still maps validation failures to IllegalArgumentException:

private def routingOf(value: String): IO[IllegalArgumentException, Routing.Type] =
   Routing.make(value).toZIO.mapError(e => new IllegalArgumentException(e))

• Suggested Approach:

  1. Introduce a domain error ADT for routing failures (e.g., sealed trait RoutingError with a InvalidRouting case).
  2. Update routingOf to return IO[RoutingError, Routing.Type] and map the validation message into that error.
  3. Adjust public APIs (create, findById, etc.) and tests/examples to reflect the new error type.

• Acceptance Criteria:

  1. No IllegalArgumentException remains in the example module for routing validation.
  2. New domain error type(s) in example app.
  3. Tests/examples compile and demonstrate the typed error channel.