This was the very first thing I thought of when I saw this submission title! Great talk, well worth watching.

My team watched this several months ago now. "Eyeball statistics" he mentions at one stage has been a phrase that has particularly stuck for us from it. So many metrics dashboards etc rely on it to a disturbing degree, if you step back and really think about what it's _actually_ showing you. I almost want to put a warning banner on most of ours. "Beware Eyeball Statistics!"

The other one is 99th percentile latency. Lots of people think of 99th percentile latency as the latency that 1% of their users will encounter. But if your site loads 200 assets, almost every site load will hit 99th percentile latency.

Yup! That's the one!