Slack
Slack's Real-Time Backbone: Flannel and the Websocket Fleet
How Slack built the Flannel edge cache and a websocket gateway tier to hydrate huge workspaces instantly without hammering primary databases.
3 min read
Tag
Real-Time Systems
5 articles
Discord
Routing Millions of Voice Calls Through Discord's SFU Infrastructure
How Discord's voice chat scales using selective forwarding units, UDP-based media transport, and globally distributed voice servers close to users.
3 min read
Twitter
Earlybird: Real-Time Search Over Twitter's Firehose
How Twitter built Earlybird, a Lucene-based inverted index engineered to make freshly posted tweets searchable within seconds of being sent.
3 min read
Discord
Presence and Read States: Keeping Millions of Discord Clients in Sync
How Discord keeps online status and per-channel read state consistent across millions of simultaneously connected clients without collapsing under fan-out.
3 min read
Discord
Why Discord's Gateway Runs on Elixir and the BEAM
How the Erlang VM's lightweight process model and fault isolation made Elixir the right fit for Discord's connection-heavy real-time gateway.
3 min read