Where did expansion go?

A product strategy question from a product manager interview, set at Fernpage, a fictional productivity saas / docs and wiki (plg) company.

The question

Skills this case tests

A starting structure

NRR = 100% − churn − contraction + expansion; expansion = seat adds + plan upgrades

How to approach this case

Begin by clarifying how NRR is measured: the period, the cohort and what counts as expansion. Then decompose it into churn, contraction and expansion and see which part moved most. The prompt points at seats, but confirm it with numbers. Check acquisition too, so you know whether the problem sits inside existing accounts. Next, look at timing. When did seat growth start slowing, and what changed in the product, pricing or billing around then? Think about the path a new person takes into a paid workspace and where they might stop before becoming a paid seat. Then find what makes healthy accounts grow. Generate options for end users, admins, other teams and sales, and rank them by impact, confidence and effort. A strong close gives a sequenced plan with rough sizing, guardrails that protect product-led growth, and a test design.

The full method for strategy, pricing and growth questions

After the mock interview you get scores on five skills, what to fix with quotes from your answers, and the ideal path for this case.