Design a Personalized News Feed Aggregator
RipplingSoftware Engineer · Onsite
Last updated
Design a personalized news-feed system that ingests articles from many sources and builds a home feed. Connect requirements and APIs to data modeling, consistency, scaling, failure recovery, observability, and the important design trade-offs.
Design a personalized news-feed system that ingests articles from many sources and builds a home feed.
Users may follow topics and sources. A new user with no preferences should receive a reasonable default mix. Breaking news must be eligible for prominent placement for all users without permanently overriding personalization. Compare fan-out-on-read with fan-out-on-write and select a hybrid strategy.
Constraints & Assumptions
- An article may arrive more than once from syndicated sources.
- Feed results need deterministic pagination while new articles continue to arrive.
- Source and topic preferences can change.
Clarifying Questions to Ask
- What defines breaking news and who is allowed to assign that status?
- How fresh must ordinary and breaking items be?
- Do users need strict exclusion or only ranking preferences for sources and topics?
Hints
Hint 1
Treat the feed as a merge: Candidate sets can come from subscriptions, precomputed defaults, and a small breaking-news lane before ranking and deduplication.
Follow-up questions
- How would you correct a falsely labeled breaking story?
- How would you avoid showing five syndicated copies of the same event?
- What changes for a user following thousands of sources?
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