Design a News Feed – Clarify

Before designing, ask:

1. Scale: DAU? Posts per user per day? Follow graph (average followers/following)?
2. Ordering: Chronological or ranked? If ranked, what signals?
3. Real-time: Sub-second freshness or eventual (e.g., 1min delay OK)?
4. Scope: Just feed, or also post creation, likes, comments?

Example Questions

• "What's the expected DAU and posts per day?"
• "Is the feed chronological or algorithmic?"
• "Do we need real-time updates?"

Inline Check 1

Why is it important to clarify scale before proposing an architecture?

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