Non — blocking, asynchronous I/O APIs make your applications more resilient, responsive and cost effective. In this blog post we will look… — Non — blocking, asynchronous I/O APIs make your applications more resilient, responsive and cost effective. In this blog post we will look at the problems blocking I/O is causing, at how non-blocking I/O solves the problems and then apply these principles to the every-day use case of file uploading.