Hard Design: News Feed (Facebook/Twitter)

What approach does Facebook use to serve a single user's news feed from pre-computed data?

— Tests your understanding of this concept.

Answer Options

A Dynamic SQL query on every request

B Pre-computed feed stored in Redis sorted set, hydrated with full post data on read

C Store full post content in Redis

D Query each followed user's timeline separately and merge

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This question is from the Design: News Feed (Facebook/Twitter) topic (System Design Cases).

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