When raw data becomes overwhelming, we turn to abstraction to understand our world. In our systems, the data is always overwhelming. Solutions like summary statistics have come to our rescue, and they are good—up to a point. In order to truly understand our systems, we need to know when and how to sidestep those abstractions,to get deep, detailed performance insight. In this brief diatribe inspired by John Rauser’s 2011 Velocity keynote “Look at Your Data”, I’ll explore techniques for visualizing the underlying structure of performance data and how this empowers drilling down to populations and individual samples in the data set.