Yes but with a heck of a lot more overhead than;

  response.body = result[(int)hexCode];

No, with a lot less overhead because you don't need to write custom web server code.

Edit: and if he points the requests directly at blob storage as he's suggesting, we're very close to to flat files on a filesystem again.

You can do that after mmap(2) and you never have to reach out for read(2). Might need to use unsafe language constructs though.