What's a typed error channel and how could it look like in Scala 3?

Looking for a union type in Scala 2.x? Look no further! Let's have a look at how we can use Shapeless coproducts for type-safe error handling.

Phantom types? A very cool technique to create more robust code! We'll be looking at the traditional builder pattern in Java and how we can create a compile-safe version in Scala.