HOW DISCORD CAN SERVE MILLIONS OF USERS FROM A SINGLE SERVER

Summary from the TLDR Web Dev newsletter

Discord handles millions of users on its servers by optimizing its system using technologies like BEAM (Erlang Virtual Machine) and Elixir. BEAM's lightweight processes and message-passing capabilities enable high concurrency, while Elixir simplifies Erlang's syntax. Discord optimized its fanout system for updates by using Elixir processes to help manage servers and user clients.