Product design question

Design a pinning feature in a chat app such as WhatsApp.

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

Feature design skill: scoping a small utility feature, its interaction model, and its edge cases.

Clarify the use case: pinning messages within a chat versus pinning entire chats to the top of the chat list.
Assume this is about pinning messages within a conversation, since chat pinning already exists.
List pain points: important info like an address or link gets buried in long threads, especially in group chats.
Prioritize group chats, since burial is worse there than in one to one chats.
Propose a pin action from long press, a pinned messages bar at the top, and a cap of 3 pins per chat to avoid clutter.
Define success as fewer scroll back searches and steady use of the pinned bar in active groups.

Distinguishes message pinning from chat pinning clearly instead of conflating the two.
Sets a concrete limit, 3 pins per chat, to prevent the feature becoming another cluttered list.
Gives an illustrative number, for example assuming 15 percent of group chats with 10 plus members use pinning weekly.
Addresses permissions: who can pin or unpin, admins only or any member.

Not specifying who can pin or unpin in group chats, a common real complaint.
Ignoring that WhatsApp already has message pinning, and not building on what exists.

Chapters of the AI PM course that teach what this question tests.