READ MF!
Requirements
Functional
- 1–1 chat
- Group chat
- user online status
- read receipts
Non-functional
Estimation
Storage
- 1 Billion users and 500 millions DAU and 10 msg per day. Each msg is 400 bytes. 500M * 10 * 400 = 2TB/day. 2TB* 400 = 800TB = 1PB
Write QPS
1B * 0.5/80,000 =6000 QPS
Read QPS
3x write 18000 QPS
API Spec
Database/Design
Database
Design
