Instagram Stories: Set a Goal, Define Success Metrics and Pick a User Group to Grow

You are the product manager for Instagram Stories. What goal would you set for Stories, and how would you measure whether it is succeeding? Once you have answered, the interviewer introduces three groups of users and asks which one you would focus on. ### Clarifying Questions - Should I treat Stories as it is today, a mature format most active Instagram users already know, rather than as a newly launched feature? - Is the goal a target for the next planning cycle, or the lasting purpose Stories serves inside Instagram? - Does my scope cover both making stories and watching them, or only one side? ### Part 1 — A goal and success metrics for Stories Set a goal for Instagram Stories and explain how you would measure success against it. ```hint Start from what Stories adds Ask what Stories gives people that a regular feed post does not, and which side of the product, posting or watching, has more room to grow today. Let that choice shape the goal before you list metrics. ``` #### What This Part Should Cover - A goal grounded in the role Stories plays inside Instagram and in its stage of maturity. - A precisely defined primary metric, with supporting metrics across posting, watching and responding. - Guardrails that protect the rest of Instagram and the experience of people who watch stories. ### Part 2 — Choosing a user group to focus on The interviewer describes the three groups only this briefly: - **Group 1:** shows up every day. - **Group 2:** a 50% chance that one-third of Group 1 shows up every 15 days. - **Group 3:** a 20% chance that one-third of Group 1 shows up every 30 days. Which group should Stories focus on, and why? Part of the task is deciding how to read these descriptions. ```hint Put the groups on one scale Choose one reading of the descriptions, then write down each group's size and expected visits over the same 30-day window. Compare where each group could go from there and how hard it would be to move them. ``` #### Clarifying Questions for this Part - Does "showing up" mean opening Instagram, watching at least one story, or posting a story? - Are Groups 2 and 3 separate sets of users, each one-third the size of Group 1, and does each probability apply to every user individually or to the whole group at once? - Is the focus meant to add visits, add story posts, or keep users from lapsing? #### What This Part Should Cover - A stated interpretation of the group descriptions, with each group's size and expected activity worked out. - A choice justified by headroom, how responsive the group is likely to be and fit with the Part 1 goal. - How you would act on the chosen group and confirm it worked without hurting the others. ### What a Strong Answer Covers - One consistent argument running from the goal through the metrics to the group choice. - Attention to both posters and viewers, and to the loop between them. - Explicit assumptions wherever the prompt is ambiguous, with the arithmetic shown. - Trade-offs with the rest of Instagram, such as feed posts and messaging. ### Follow-up Questions - Story posting rises after your change, but feed posting falls. How would you decide whether the change was a win? - If you focus on Group 2, which experiment would you run first, and how would you keep friends' activity from contaminating the test? - What evidence would make you switch your focus to Group 3?