Why Is Everything P0?

While digging around in my notes app I found this old essay from my time at Meta Reality Labs that was originally posted internally. We were right in the middle of a team wide planning cycle and, as always, things were getting tense. At the time, we were using the very popular P0, 1, 2, 3, 4 system for prioritisation and, in a way that's probably very familiar to you all, everything was P0...…