One suggestion would be to make the description of how it works a little clearer. For example, "No status handling. Prosessing & error messages will be shown through video" could say, "While the video is being processed, a temporary video file will be streamed - with the text "Processing" written on it." like you said in the comments. Also, will transcoded videos be saved in my S3, or in transcode.io's?
I will make these updates. The transcoded file will be saved in transcode.io 's S3.
( A quick question: If I update code to heroku, will it pull the site down, even for a few minutes? )