Non-functional requirement

1. Latency: Minimum
2. Availability: High
3. Consistency: Eventual (Due to CAP theorem)
4. Ready-heavy

Estimation

1. 1B DAU
2. 10B news feed requests per day
3. 2 user posts per day per user
4. 200 friends per user
5. 100 pages followed by each user

DB

• Entity: User, Entity, FeedItem, Media
• Relationship:
  • UserFollow: m:n
  • FeedMedia: 1:n

High-level

Feed generation

Feed publication