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System Design Quiz Practice
Active Recall Drill Session
← Exit Session
Question 1 of 1
medium
System Design
Why does the notification system's in-app unread badge count need to be a durable database value rather than purely derived from live WebSocket events?
A
Databases are always required for any counter
B
A user could be offline/disconnected when some notifications fire, missing those live events entirely — the true count needs to reflect ALL notifications, not just ones received while actively connected
C
WebSocket events cannot carry numeric data
D
This is an arbitrary implementation choice with no real justification
Check Answer