From Heroku:
Hi,
While there aren't any size restrictions on requests such as these, you're most likely going to run into the 30-second timeout problem. The only way around the timeout is with long polling, as described here. I'm not aware of any drop-in implementations of this for file uploads, though. I'm guessing this traffic is coming from an app or something that makes it impractical to implement Cloudinary's direct upload out of the box. Are there other reasons you couldn't adapt Cloudinary's direct upload solution? I'd like to get their input on this as well.
Thanks,
Chad