Mid-level interview questionAsked at Perplexity · interview write-up
Design personalized discovery recommendations for an AI answer engine, from event logging and candidate retrieval to ranking and feedback loops.
Model answer
Log impressions, clicks, dwell, follow-up questions and shares, with position, so you know what was shown and ignored. Retrieve candidates from embeddings of the user's past queries, trending stories and editorial picks, and rank with a model predicting engaged reads, not clicks alone. Add freshness and diversity rules.
Guard against feedback loops: reserve a little traffic for exploration and correct for position. Evaluate offline on time-split logs, then A/B test retention.
Practise the rest
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