What is a North Star metric, and how does it relate to input metrics?
PICTURE THIS: HOW TO EXPLAIN IT
Simple meaning
A North Star is the current best single measure of delivered customer value, such as weekly retained collaborative documents.
WHY — Business Metrics instead of guessing?
Why interviewers care about Business Metrics:
people who only read docs from people who shipped.
and tied to Data Science work.
Name the idea, why it exists, then one short example.
End with when you use it and one common pitfall.
STEPS — What happens step by step?
Before you speak the answer, walk the interviewer through these steps:
- 1A North Star is
the current best single measure of delivered customer value, such as weekly retained collaborative documents.
- 2Input metrics are leading
levers you can move in experiments, like invite sends, that should connect causally to the North Star.
- 3Optimizing a vanity input
that does not flow through will Goodhart the dashboard.
- 4Give an example
One tiny concrete case you can say aloud.
- 5Common mistake
What juniors usually get wrong.
- 6Close
When you pick this over the alternative.
EXAMPLE — See it in action
Here's a short line you can speak, broken into clear beats:
Note: Adapt this scaffold to your own project — keep it under 60–90 seconds.
Key takeaway
A North Star is the current best single measure of delivered customer value, such as weekly retained collaborative documents. Input metrics are leading levers you can move in experiments, like invite sends, that should connect causally to the North Star.