// TOPIC
#ranking
4 articles
◆◆IntermediateRiot GamesActivision
01Design a Real-Time Leaderboard (gaming)
Rank millions of players by score and answer "top N" and "my rank" instantly. Redis sorted sets, sharding by score range, and approximate ranks at scale.
#interview#ranking#caching
22 min◆◆◆AdvancedNetflixAmazon
02Design a Recommendation System (Netflix / TikTok)
Pick the best items for each user from millions of candidates in milliseconds. The two-stage candidate-generation + ranking architecture, embeddings, and feature stores.
#interview#ml#ranking
22 min◆◆◆AdvancedMetaInstagram
03Design Instagram (photo sharing)
A photo-first social network — uploads, image processing, feed, stories, and global delivery.
#interview#feed#storage
18 min◆◆◆AdvancedMetaInstagram
04Design a News Feed (Facebook / Instagram)
How Meta builds the home feed — fanout, ranking, candidate generation, and how the same architecture serves billions.
#interview#feed#fanout
16 min