[janko-m]

I feel the same as you. Refile was first very exciting for me, because if you wanted to change a version, you don't have to reprocess them, you only have to change the URL in the HTML. But that means that if you have a page with lot of these images, it would be super slow and can really easily DoS your server. And CDNs also cache the images for like 4 hours, which is terrible. I realized it's much better to just have the thumbnails done immediately.

Yes, I was inspired by CarrierWave's uploaders, the goal of Shrine is to have all of the uploading logic in the uploader. And it even allows you too hook up to ".included" of the model that receives the attachment methods, from inside the uploader (http://shrinerb.com/rdoc/classes/Shrine/Plugins/Included.htm...).