Metric trees: breaking a goal into parts

#Why trees matter in interviews

A north star is an output. Nobody can move "weekly attended classes" directly. Teams move the things underneath it: how many people sign up, how many book, how often they come back. A metric tree is the map from the top number down to those parts.

You will use trees in three places in this module:

• Diagnosing a change. The tree tells you where to slice first.
• Setting goals. The tree shows which part a feature can move, and by roughly how much.
• Trade-offs. The tree shows which parts are moving in opposite directions.

An interviewer who hears you split the metric before guessing causes will mark you as structured. One who hears fifteen causes listed off the top of your head will not.