Entities in our codebases will commonly need identifiers or IDs to refer to them with. We will have a look at the different options for them and how to make them type-safe, allowing our code to be safer and less error-prone.
Modelling a type that can come in different forms, each with their own state, is a really handy language feature. We will look into how and when Kotlin sealed classes can be used and look at some use cases for them!