Here are some pointers: "Our approach to blocking links" https://help.twitter.com/en/safety-and-security/phishing-spam-and-malware-links https://help.twitter.c

Here are some pointers: "Our approach to blocking links" https://help.twitter.com/en/safety-and-security/phishing-spam-and-malware-links https://help.twitter.com/en/safety-and-security/phishing-spa... "The Infrastructure Behind Twitter: Scale" https://blog.twitter.com/engineering/en_us/topics/infrastructure/2017/the-infrastructure-behind-twitter-scale https://blog.twitter.com/engineering/en_us/topics/infrastruc... "Mux" https://twitter.github.io/finagle/guide/Protocols.html#mux https://twitter.github.io/finagle/guide/Protocols.html#mux I do agree that some of this could be done better a decade later (like, using Rust for some things instead of Scala), but it was all considered. A single machine is a fun thing to think about, but not close to realistic. CPU time was not usually the concern in designing these systems.