YOUTUBE a-BOSpxYJ9M Dave Thomas presents at GOTO 2015
This is an extremely cynical talk about how an industry was built up around the "Agile Manifesto". Thomas says that the title should have been "The Manifesto for agile software" using agile as an adjective, and that it all went wrong when it started being used as a noun.
Thomas criticizes the Ruby community for being dogmatic about tests and shunning people who don't do them. He describes testing as a way of discovering how an interface works but doesn't aim for 100% test coverage.
24:03 Reclaim Agility
Thomas want's to reclaim Agility following simple rules. First you find out where you are, take a small step towards your goal, adjust your understanding based on what you learned and then repeat.
He says you can apply this over and over again to small and large problems, even when you're choosing the name of a variable.