Backend · Mid-level · System design

Design a notification service that, based on events from other services, sends users email, push notifications and SMS, at up to several million notifications a day.

~10 min by voice

How to approach it

This checks whether the candidate can build an asynchronous message delivery pipeline: a broker instead of synchronous calls, independent channels, reliability (retries, DLQ, idempotency) and the real constraints of external providers. Interviewers also watch whether they remember the user: preferences, priorities, no duplicates.

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Topics

system design message queues notifications

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Answer by voice

The interviewer will ask this question and listen. Think out loud and ask for a hint if you need one. When you're done, pause or tap “That's my answer”. In about a minute, your score and the points you covered show up here.

Best with headphones · ~10 min