I'm not saying it can't be done. In fact the multipart parser we have build for transloadit has already been ported to C++ [1] and I imagine Java has decent lib

I'm not saying it can't be done. In fact the multipart parser we have build for transloadit has already been ported to C++ [1] and I imagine Java has decent libraries as well. But most people just sit on a request/response oriented Python/Ruby/PHP stack with possibly stupid buffering load balancing in between (nginx buffers uploads). If you build this from ground up, it is certainly possible with a lot of technologies. [1] https://github.com/FooBarWidget/multipart-parser https://github.com/FooBarWidget/multipart-parser