// TOPIC
#websocket
3 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◆◆◆AdvancedGoogleMicrosoft
02Design Google Docs (real-time collaborative editor)
Multiple people editing the same document simultaneously, every keystroke synced, never a corrupt merge. Operational Transformation, CRDTs, presence, and the architecture that's run quietly at Google for 17+ years.
#interview#realtime#collaboration
21 min◆◆◆AdvancedMetaDiscord
03Design WhatsApp / Chat System
Realtime 1:1 and group messaging at billions-of-users scale. WebSocket gateways, message store, presence, end-to-end encryption.
#interview#realtime#websocket
16 min