TRAFFIC 101: PACKETS MOSTLY FLOW

Summary from the TLDR Web Dev newsletter

Slack handles billions of inbound network requests per day, all of which traverse through its edge network and ingress load-balancing tiers. This blog talks about how a request flows — from a Slack user’s perspective — across the vast ether of the network to reach AWS and then Slack’s internal services. Slack uses websocket connections for sending and receiving messages and edge APIs for everything else.