The 60-second answer
Start with location/privacy constraints, intent, freshness, and the product objective such as useful visits rather than clicks alone. Retrieve geographically eligible candidates, then rank using travel time, preferences, context, quality, popularity, open-now status, and novelty.
Build the answer in this order
Start with location/privacy constraints, intent, freshness, and the product objective such as useful visits rather than clicks alone.
Retrieve geographically eligible candidates, then rank using travel time, preferences, context, quality, popularity, open-now status, and novelty.
Handle sparse/new users and new places with contextual/content priors plus controlled exploration.
Evaluate recall, NDCG/engagement, saves/visits, negative feedback, geographic slices, latency, and marketplace fairness.
A useful interview mental model
This is the shape of a strong answer—not a script to memorize.
Senior-level signal
- Senior answers discuss exploration, geographic supply bias, and privacy-preserving location handling.
- Include real-time availability/freshness and distinguish retrieval misses from ranking mistakes.
What the interviewer is really testing
Likely follow-up questions
Common weak-answer patterns
- Jumping to a model before defining the product contract.
- Listing components without bottlenecks, metrics, or failure handling.
- Ignoring data quality, serving latency, monitoring, and iteration.