System designMediumsd-p087

Subject Queues streamingLevel Mid–Senior~45 minCommon in Distributed systems interviewsIndustries Technology, Software development

Question

Design a notification feature that batches many individual notifications into a digest ('You have 5 new comments') instead of sending each separately.

What a strong answer looks like

Clarify scale and constraints first. Propose a clean component breakdown, then go deep on the hard parts — data model, bottlenecks, consistency, failure modes — and name the trade-offs you are making.

Learn the concepts

Narrate your design

Loading whiteboard…

Run or narrate your approach, then ask the coach.