Beazley's Concurrency From the Ground Up is one of my favorite tech talks ever: In about 45 minutes he builds an async framework using generators, while live coding in an emacs screen that shows only about 20 lines and without syntax highlighting, and not breaking stride with his commentary and engaging with the audience.
It's 8 years old, but definitely worth a watch: https://www.youtube.com/watch?v=MCs5OvhV9S4