Does anyone have any experience plugging into an Amazon gpu cluster in a web app? Is it even possible? I want to make an online interface to a simulator I have written in cuda, but everything I have seen so far involves ssh and the command line.
Yes, this is very possible!
You may want to consider binding your CUDA C code (I'm just assuming C) to your preferred scripting language for better efficiency if you intend to build the front end logic not in a lower level programming language but absolutely this is possible.
Keep in mind, many web developers build their apps strictly from the command line, you simply need to find an effective and efficient way of calling the CUDA code from your Web app and then simply return the results to the client who made the request.