Choose a North Star and Health Metrics for a Streaming Service
Company: Netflix
Role: Product Manager
Category: Analytics & Experimentation
Difficulty: medium
Interview Round: Other
Which key metrics should a streaming service capture to understand how the product as a whole is performing? Explain what success means for the service, organize the metrics you would track, and say which few you would watch most closely and why.
```hint Start from how the service earns money
Whether revenue comes from subscriptions, from advertising or from both changes which viewer behavior counts as success. Settle that first, then follow a customer from first discovering the service to renewing or cancelling, and pick at each stage the metric that best shows real value.
```
### Clarifying Questions
- Is it a video service (films and series) or an audio service (music and podcasts)?
- How does it make money: paid subscriptions only, a free ad-supported tier, or a mix of plans?
- Who will use these metrics: leadership tracking the health of the whole business, or a product team looking for signals it can move?
- Is the service mature in its main markets, or still in a growth phase where adding customers matters most?
### What a Strong Answer Covers
- A goal derived from the business model, and a north-star metric that captures real viewer value, with a reason for preferring it over obvious alternatives.
- Metrics organized along the customer journey (acquisition, activation, engagement, retention, monetization), each defined precisely enough to compute.
- Streaming-specific signals such as content performance and playback quality, not only generic app metrics.
- Guardrail and counter-metrics that stop the team from chasing raw viewing time or sign-ups at the expense of satisfaction and revenue.
- A short prioritized set, with how it would be segmented and read over time.
### Follow-up Questions
- Total viewing hours went up this quarter, but so did cancellations. How would you reconcile the two, and which signal would you trust?
- If the service added a cheaper plan with ads, which metrics would change meaning, and what new guardrails would you add?
- How would you judge whether one expensive original series was worth what it cost?
Overview: A product metrics question about which metrics a streaming service should capture to judge the health of the whole product. It tests choosing a north-star metric tied to the business model, organizing metrics along the customer journey, covering playback quality and content performance, and setting guardrails.