This was a fantastic treatment of *nix socket programming. While viewed through a ruby lens (the author relies on the ruby socket library for building client/server examples), the book does a tremendous job introducing the reader to the fundamentals of socket programming, common gotchas, and architectural patterns for building fast servers. He brings a lot of clarity to underlying servers such as nginx, puma, eventmachine, and unicorn. I cannot recommend this highly enough for those wanting to get a deeper understanding socket programming basics.