Design Patterns · Senior · Question 75 of 75

Why use queues to decouple a slow operation (e.g. generating a PDF report) from a user request?

✓Correct answer: The request returns quickly; workers process jobs at their own pace, retry failures and absorb traffic spikes
2Queues make the PDF smaller
3Queues replace the database

Explanation

The UI shows a pending status and gets notified (polling, WebSocket, email) when the job completes.

Further reading

Wikipedia: Message queue ↗

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