The fastest teams I've ever worked with have been agile. Not big-A, all-about-the-TDD, automate-everything, methodology-over-thinking Agile, but quietly-getting-on-with-business, delivering-the-goods, making-the-trade-offs agile. Think agile manifesto over agile methodology.
It turns out the things I thought were great agile practices, while useful in certain circumstances, are by no means the whole story. Kaizen, or continuous improvement, must be coupled with kaikaku, or abrupt change, in order to avoid getting stuck in the local maximum of 1990s Agile methods.
This talk is about how really high-performing teams work. Not just one or two flukes but enough that there might be something to it. The patterns and ideas in this talk are genuine experiences from active practitioners. This is agile in actuality. Agile is an attitude, not a rulebook.