Design a News Feed (Twitter / Facebook-style Timeline)

A model interview answer: requirements, numbers, fan-out on write vs read, feed cache, and the celebrity problem

Walk through a complete news feed system design interview answer with real numbers: capacity estimation, APIs, data model, push vs pull fan-out and the hybrid for celebrities, Redis feed caches, cursor pagination, sharding, and failure modes.

Practice questions (5)

• Capacity Estimation From Scratch

  Intermediate · Free
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• Choosing Between Push and Pull Fan-out

  Advanced
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• Setting the Celebrity Threshold

  Advanced
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• Why Offset Pagination Breaks a Live Feed

  Intermediate
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• Recovering From Feed Cache Loss

  Advanced
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Quizzes (1)