You're both right, although you more than the other guy being a dick. libuv uses a thread pool for asynchronous I/O for everything but network requests, which a

You're both right, although you more than the other guy being a dick. libuv uses a thread pool for asynchronous I/O for everything but network requests, which are handled on the main thread - presumably because they're already asynchronous by nature. http://docs.libuv.org/en/v1.x/design.html http://docs.libuv.org/en/v1.x/design.html