Three kind of errors I spend too much of time to resolve (but it was simple). One day you decided that it's time to start write on Haskell. After learning all the basics, you ready to create “my_first_haskell_backend_app”. There are problems you probably meet with (but after this article don't have to). Parameterized App monad When you work on at least some complex application, it’s most convenient to use…