ARCHITECTURE

Summary from the TLDR Web Dev newsletter

Slack sends millions of messages daily across millions of channels in real-time across the world. This post explores Slack’s real-time messaging architecture with a discussion on the architectural and system design concepts they leverage to scale and keep the latency low. Slack's Channel Servers are stateful and in-memory, aiding in quick message delivery to clients. The post also touches on how consistent hashing routes traffic to different Channel Server nodes. It discusses the trade-off between low latency and scalability challenges which can be mitigated using the right cloud instance for memory-intensive operations.