True, but that's Docker. There's nothing, that I know, that would make Linux containers inherently much slower than a fork. Amazon could conceivably also write

True, but that's Docker. There's nothing, that I know, that would make Linux containers inherently much slower than a fork. Amazon could conceivably also write their own container runtime that kept the container ready to run without actually starting the app (though I'm sure there's a lot more to it -- I don't know how Lambda is implemented).