https://typelevel.org/cats/typeclasses.html • Talks: ◦ Petra Bierleutgeb, Polymorphism in Scala: https://www.youtube.com/watch?v=-SA1Ui283Qc ◦ Rob Norris, ScalaX keynote: https://skillsmatter.com/skillscasts/11626-keynote- pushing-types-and-gazing-at-the-stars