@feld @p @mint @j and all the slowdown ends up being the layers of phoenix, plug, http adapter wrappers before it ends up calling out to that OTP bit

https://www.youtube.com/watch?v=xEJ1n13soWU

even the classic http://erlang.org/pipermail/erlang-questions/2011-July/059782.html thread mentions sendfile, and that's 2011