Deep-dive guide to effect polymorphism in Scala using F[_] and type classes. Write generic code that works with Cats-Effect or ZIO, then swap runtimes later. Learn EffectSystem patterns, Kleisli composition, and examples from flowforge.
Learn Kleisli from first principles to compose effectful data pipelines with Cats or Cats Effect, wiring sources, transforms, and sinks with clear errors, observability, and easy tests. Includes a Scala example you can lift into prod.