In many conversations and talks given after the late Joe Armstrong retired, he rarely talked about Erlang, and instead focused on the different expressions of the ideas that had driven it: models of concurrency based on the realities of physics, the importance of self contained code and applications, and perhaps most important of all, the importance of designing by prototyping.

For this special keynote, one of Erlang’s co-inventors and the creators of Sonic Pi and TiddlyWiki reflect on what they have learned while collaborating with Joe.