Set a North-Star Metric and Guardrails for Video on Facebook
Company: Meta
Role: Product Manager
Category: Analytics & Experimentation
Difficulty: medium
Interview Round: Other
How would you decide whether video on Facebook is a success? Define what success means for it and the metrics you would track.
```hint Goal before metrics
Settle what video is meant to do for Facebook and for the people on each side of it before naming any number; the metrics should follow from that goal.
```
### Clarifying Questions
- Does "Facebook Videos" mean the dedicated video tab, all video watched anywhere in the Facebook app (Feed, Reels, Live), or one specific format?
- Is this about the health of video as it runs today, or about judging a particular launch or change?
- Should I cover the creators who publish videos and the advertisers who buy video ads, or focus on viewers?
### What a Strong Answer Covers
- A stated goal for video within Facebook's mission and business, and the scope being measured
- The groups in the video ecosystem and the actions that show each one is getting value
- One north-star metric justified against alternatives, with supporting metrics along the funnel
- Guardrails that catch growth bought at the expense of quality, the rest of Facebook or the ad experience
- Measurement traps specific to video and how to guard against them
### Follow-up Questions
- Video watch time rises while time spent in Feed falls by about the same amount. Is that success?
- How would you tell whether more views reflect better content rather than more autoplay?
- Your north star is up, but creators say their reach and earnings are falling. What do you do?
Overview: A product analytics interview question about how you would judge whether video on Facebook is succeeding. It tests whether you can tie video to a clear goal, map viewers, creators and advertisers, choose a north-star metric with supporting metrics and set guardrails against misleading growth.