Lies, Damn Lies, and Metrics

As evidenced by Heroku's "routergate", just having your app instrumented isn't enough to actually know how things are going in the real world. Metrics frequently make people think that everything is understood and under their control, even when that is far from reality. This talk covers common blind spots in instrumentation and metrics setups. It also tries to help inculcate a mindset that cares about the real-world results rather than the dubiously accurate numbers showing up on a web page.