Understanding the exact properties that disqualify a data type from being an instance of a given abstraction turns out to be surprisingly helpful

Abstractions such as functor, monads... are often explained by example, which I think is only half of what's needed to build a solid intuition. The other half is counter-examples: things that *aren't* things. This talk intends to fill that void, by going through the list of common abstractions and showing types that are, say, a functor, but not an applicative. While this may sound more like a toy than something useful, understanding the exact properties that disqualify a data type from being an instance of a given abstraction turns out to be surprisingly helpful, and have certainly allowed me to go further in my study of such things.
Let's go through some libraries from ZIO ecosystem that will allow us to implement API layer with ZIO HTTP
How to implement fast and cost-effective backend for a multiplayer game using Scala, Akka and GraalVM
Scala is improving rapidly. This session will give you the perspective of someone in the middle of these changes.
We will look into three less-understood, yet (arguably) extremely useful constructs introduced in Cats Effect 3: Dispatcher, Supervisor, IOLocal