// TOPIC
#geo
4 articles
◆◆◆AdvancedMetaSnapchat
01Design Nearby Friends (Real-Time Friend Location Sharing)
How to stream real-time friend locations to millions of users without collapsing under the write amplification of a 30× social-graph fanout.
#geo#realtime#pub/sub
21 min◆◆◆AdvancedGoogleUber
02Design Google Maps (routing & navigation)
Find the fastest route across a continent-scale road graph in milliseconds, with live traffic and ETAs. Contraction hierarchies, live traffic weights, and tile serving.
#interview#geo#graphs
22 min◆◆IntermediateGoogleYelp
03Design Yelp / Nearby Search (proximity service)
Find restaurants/businesses near a location, fast. Geohash, quadtree, hexagonal cells, and the right index for "within 5 km of me".
#interview#geo#search
16 min◆◆◆AdvancedUberLyft
04Design Uber / Lyft (ride hailing)
Match drivers to riders in real time at city scale. Geohashing, dispatch algorithms, surge pricing, and the realtime location pipeline.
#interview#geo#realtime
17 min