Hey-hey-hey! So you decided that it's not cool to use http4s with Cats any more. It's obvious that you may want to see in action ZIO as a more progressive Scala library for functional programming. Fortunately it's easy to start using ZIO in your http4s app, and I've seen personally several articles about that. But I decided to write my own recipe :)
There are three things a software developer can watch forever: fire, water, and request validators. In the previous blog post I demonstrated how to develop a simple REST API application with http4s. But that app has a drawback — user can send any invalid data to the API and it will be processed with no error messages.
So you decided to try http4s to create some web app or an API. Naturally your first step is to read official docs. Then you may notice that it's not helpful at some point (there you see just some syntax and general approaches to deal with common http stuff). Finally you start google for some http4s examples, preferably with CRUD, because it's almost a standard way to start acquaintance with new http library.