Product design question

How can you increase 7-day retention for new users on Messenger?

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

Tests retention-focused product thinking: can you identify what drives early habit formation in a messaging app and propose a testable intervention.

Clarify the target: new users in their first week, where the goal is forming a messaging habit before they default back to another app (iMessage, WhatsApp).
Identify why new users churn early: often a lack of contacts already on the platform (network effect gap), not knowing the app's differentiated features, or a clunky first-use experience.
Prioritize the contact-network gap as usually the biggest lever, since messaging apps live or die on who else is already there.
Propose a concrete intervention: a smarter contact-import and invite flow that shows a new user exactly which of their existing contacts are already on Messenger, plus a low-friction one-tap invite for the rest.
Propose a secondary intervention: a guided first-week nudge highlighting a differentiated feature (like disappearing messages or group chat games) to build habit beyond plain texting.
Define success as D7 retention specifically, and a supporting metric like percentage of new users who send a message to at least three distinct contacts in week one.

Identifies the network-effect gap as the likely root cause, which is specific to messaging apps and not generic retention advice.
Proposes a concrete, buildable mechanism (contact-match plus one-tap invite) rather than a vague 'improve onboarding'.
Adds a behavioral proxy metric (messaged three distinct contacts in week one) that predicts retention better than a single login-based metric.
Separates the acquisition-of-contacts problem from the feature-discovery problem as two distinct levers.

Proposing generic engagement gimmicks like push notifications without addressing the underlying network-effect gap.
Treating D7 retention as a single lever instead of breaking down what actually drives it in a messaging context.
No proxy metric to catch the behavior early, relying only on the lagging D7 number itself.

How would you handle users who have very few contacts already on the platform?
What would you A/B test first to validate the contact-import hypothesis?
How would this strategy differ for a user acquired via a group invite versus an app store search?