HardDesign: Notification System
What is the recommended way to handle a user who uninstalls your app but still has their device token in your database?
— Tests your understanding of this concept.
Answer Options
AKeep the token forever
BDelete immediately on app uninstall event
CFCM/APNS will return an invalid token error — remove token on first delivery failure
DRefresh the token automatically
Want to see the correct answer?
Get the answer with a detailed explanation, plus practice 22+ more Design: Notification System questions with adaptive quizzes and timed interviews.
See the Answer on Guru Sishya →This question is from the Design: Notification System topic (System Design Cases).
More Design: Notification System Questions
What is the difference between FCM and APNS?
HardWhat happens when you try to send a push notification to an invalid/expired device token?
HardHow do you implement 'quiet hours' — not sending notifications between 10pm and 8am in user's local time?
HardYour email notification service sends 2 million emails/day. SendGrid has a 4-hour outage. How do you handle this?
HardWhat legal requirement mandates that marketing emails include an unsubscribe link?
Hard