This is an unofficial PDF version of "Category Theory for Programmers" by Bartosz Milewski, converted from his blogpost series (with permission). Category Theory for Programmers was published 12 August, 2019. Based off release tag v1.3.0. See errata-1.3.0 for changes and fixes since print. Scala Edition is now available in paperback. Publish. Based off release tag v1.3.0. See errata-scala for changes and fixes since print. The best way to build the book is using the Nix package manager. After...