felleisen

Matthias Felleisen's keynote uses weather prediction as an analogy for type systems, arguing they forecast problems so you can act on them. It draws on his experience developing Typed Racket.

Shriram Krishnamurthi's PWLConf 2019 talk on the formal notion of expressive power of programming languages, based on Felleisen's paper. It explains how to tell when a feature adds power by whether emulating it requires global rewriting.