Metrics question

What metrics will you use to calculate the happiness index of customers for the Medium blog?

Practice this question out loud. An AI interviewer asks it, follows up like a real interviewer would, and scores your answer. Type or speak.

What this question tests

Metrics design skill for a qualitative concept, happiness, forcing you to build a proxy metric tree grounded in behavior.

Clarify what happiness means here, likely reader satisfaction and writer satisfaction are both relevant for Medium's two-sided model, so confirm which side is in scope.
Break happiness into observable proxies rather than trying to measure it directly: engagement depth, return behavior, and explicit feedback.
Propose reader-side metrics: time spent reading relative to article length, return visit frequency, and claps or highlights per session.
Propose writer-side metrics if in scope: publishing frequency, follower growth, and earnings via the partner program.
Add a direct signal, a periodic short survey like NPS, to validate that behavioral proxies actually track satisfaction.
Combine into a composite index, but flag that any single proxy can be gamed, so use multiple signals together.

Distinguishes reader and writer happiness explicitly, since Medium is two-sided and a single index would hide tension between the two.
Proposes a specific proxy, completion rate as a percentage of article length read, as more meaningful than raw time spent.
Adds NPS or a lightweight survey as a validation layer against gamed behavioral metrics.
Notes a guardrail, watching for happiness metrics rising while overall usage falls, which would signal a shrinking but more satisfied base.

Proposing only one metric, like time spent, as a full proxy for happiness.
Not separating reader and writer perspectives on a two-sided platform.
Ignoring the risk that behavioral proxies can be gamed without a direct feedback signal.

How would you weight reader happiness against writer happiness if they conflict?
How would you detect if your happiness proxy was being gamed?