System Design: Yelp

Design a local-business directory that combines nearby-place search with business details, photos, and reviews. The central question is how to find relevant candidates inside a radius without scanning every place.

What is Yelp?

Yelp connects consumers with local businesses through listings, photos, ratings, and reviews. This case study models a subset of that experience, rather than documenting its current internal architecture.

A user provides a query and a location, and the service returns matching nearby places. A proximity server narrows the geographic candidates before checking category, text, and distance. Spatial indexes such as quadtrees or geohashes are design options, not the only possible implementation. Search also needs a ranking rule: the closest cafe and the highest-rated cafe need not be the same result.