Metrics question
It's Instagram in 2013. How would you define success for the team whose charter is to build the first API?
Practice this question out loud. An AI interviewer asks it, follows up like a real interviewer would, and scores your answer. Type or speak.
Start a mock interview on this question · Mock interview from a job description
What this question tests
Metrics thinking for a developer platform in its earliest days, where the customer is other developers, not end users.
How to approach it
- Clarify the charter: this is a platform team, so success should be measured by developer adoption and ecosystem health, not consumer engagement.
- State the goal: get third party developers building useful integrations that keep users engaged with Instagram indirectly.
- Build a metric tree: number of registered developer apps, number of active API calls per day, and developer retention (apps still active after 90 days).
- Add a quality metric: percent of API calls that succeed without errors, since early platform APIs are often unreliable.
- Set a guardrail: API usage should not create spam or low quality third party apps that damage user trust in Instagram.
- In 2013, prioritize developer trust and reliability metrics over raw volume, since this was Instagram's first API and mistakes would be costly to the ecosystem's reputation.
What a strong answer includes
- Frames developers as the real customer for a platform team, and picks metrics like active integrations and API reliability accordingly.
- Adds a quality guardrail against spammy third party apps, reflecting a real risk platform APIs faced in that era, like the abuse Twitter's early API saw.
- Sequences priorities correctly for a brand new API: reliability and trust first, volume and scale metrics later.
Common mistakes
- Measuring this like a consumer feature (daily active users) instead of a developer platform.
- Ignoring platform abuse risk, which was a real, well known problem for early social APIs.
Likely follow-up questions
- How would you handle developers who build apps that violate platform guidelines?
- What would make you shut down or restrict API access if things went wrong?
More metrics questions
- How would you measure the success of Facebook Likes?Meta · Metrics · Medium
- How would you measure improvements made to Facebook messenger?Meta · Metrics · Easy
- Imagine you are the PM in charge of Reactions on Facebook - the new way to interact with posts by using “love”, “haha”, “wow”, “sad”, and “angry” reactions. What would success look like in terms of number of non-like reactions per post at launch and how do you come up with this? Would this number differ by reaction? Why or why not?Meta · Metrics · Hard
- You launched a new signup flow to encourage new users to add more profile information. A/B test results indicate that the % of people that added more information increased by 8%. However, 7 day retention decreased by 2%. What do you do?Google · Metrics · Hard
- Define the metrics for YouTube search.Google · Metrics · Medium
- You are the PM of Instagram app. The MAU has been constant but DAU has declined. What will you do?Meta · Metrics · Medium
More questions from these companies
Learn the skill behind it
Chapters of the AI PM course that teach what this question tests.
- Chapter 9: Prove it paid off: outcomes, economics, and pricing
- Chapter 2: Data fluency: SQL, logs, and reading the truth yourself
- Chapter 14: Get the job: the AI PM interview loop