Actually that’s not totally accurate. The native IO model in the Win32 subsystem, I/O completion ports, is indeed completion based. But the NT kernel does have

Actually that’s not totally accurate. The native IO model in the Win32 subsystem, I/O completion ports, is indeed completion based. But the NT kernel does have a scalable readiness model too, limited to sockets, that people have used to build an epoll(). See: https://github.com/piscisaureus/wepoll https://github.com/piscisaureus/wepoll. This is used by e.g. deno and node.