Instagram · Metrics · Mid · 45 to 60 minutes

How should Instagram measure Reels?

Instagram is a social app where people create, share, and discover photos, videos, and messages. Answer this product management case and get it graded line by line against a weighted rubric.

metric design
product judgment
strategic thinking
ecosystem thinking
written communication

The situation

You are a PM on Instagram's short video team. Product leadership asks you to recommend how the company should measure Reels before it gets more investment and more prominent placement in the app. Reels could help Instagram win more short form video attention and give creators another way to reach people, but the team is worried that a narrow focus on views could reward shallow engagement or pull usage away from photos and Stories, which are still core parts of Instagram. Several partner teams want one success dashboard, but they disagree on what matters most: viewer engagement, creator participation, or overall time spent. Your manager wants a metrics framework that can align ranking, creation, and growth decisions for the next two quarters. You need to define the product goal, recommend primary and supporting metrics, and set guardrails that would show if Reels is growing in a way that hurts the broader Instagram experience.

What to produce

Write a 1 to 2 page metrics strategy memo.

Your answer must

State the product goal for Reels in one clear sentence, including whose value the product is meant to create.
Recommend one primary success metric and 3 to 5 supporting metrics, with precise definitions for each.
Cover both sides of the marketplace by including metrics for viewers and creators.
Include 2 to 4 guardrail metrics that would detect harm to core Instagram surfaces such as photos and Stories.
Explain how you would interpret metric movement, including at least one important trade off or failure mode.
Name the key cuts or segments you would review regularly, such as user type, creator cohort, or surface entry point.

Constraints

Do not assume access to new user research or a major product redesign before this framework is used.
Use metrics that Instagram could plausibly measure from in app behavior and existing logs.
Your framework should help near term product decisions over the next two quarters, not serve as a full company scorecard.

Format

Use short sections: goal, primary metric, supporting metrics, guardrails, and review plan.

How Instagram actually played it

A metrics case on measuring Instagram Reels. The answer states the goal for the product, defines success metrics across creators and viewers, and adds guardrails to avoid hurting the core photo and Stories experience.

Metrics are a tool for persuading teams, so be precise about definitions
Cover both creator and viewer sides of a content product
Guard against cannibalizing existing surfaces

Built from Facebook PM Interview: Instagram Reels Metrics by Ajitesh, Tough Tongue AI (PM Interview Prep Weekly).