LinkedIn rebuilds its feed: FollowFeed is 5x faster on half the servers

LinkedIn replaced its old Sensei search engine with FollowFeed, a system its team spent 20 months building. The new feed is assembled at query time, runs 5x faster, holds 20x more data and uses half the servers.

• FollowFeed is 5x faster, holds 20x more data and runs on half the servers
• The feed is never stored: it is built per request from 720 permanent partitions
• Data lives in RocksDB on SSD, and scoring runs on the index nodes themselves
• Mobile feed queries land at roughly 140 ms at p99