HardSocial Media45 min

Design a News Feed (Facebook/Twitter)

Design a social media news feed that aggregates and ranks posts from followed users and pages.

MetaTwitter/XLinkedInTikTok

Functional Requirements

Users see posts from people they follow, sorted by relevance
Support text, images, and video posts
Near real-time: new posts appear within seconds
Handle celebrities with millions of followers
Support likes, comments, and shares

Steps (0/6)

Step 1: Clarify Requirements

Scale: 500M DAU. Each user follows ~200 people. Average user scrolls 5-10 feed requests/session. Feed consists of posts from followed users. Key question: Chronological or ranked feed? Usually ranked by relevance (engagement signals, recency, user affinity).

Key Points

500M DAU, ~200 follows per user average
Feed generation: ~500M × 10 = 5B feed requests/day
Post creation: ~100M new posts/day
Feed should be personalized and ranked

1 / 6