[rubinelli]

Can you generate low-resolution intermediate images and only create the full-resolution image in the end? What if you changed your UI to display some kind of thumbnail timeline? Another operation, another generated thumbnail (taking, let's say, 5k) is added to the list. This adds some interesting benefits, like letting your users compare and revert changes easily. When the user is done, you can upload the finished product to S3, and maybe ask unregistered users to create a free account before you return the link.