We built a video transcoding platform in Rails - http://zencoder.tv http://zencoder.tv and http://flixcloud.com http://flixcloud.com. Of course, it would be stu

We built a video transcoding platform in Rails - http://zencoder.tv http://zencoder.tv and http://flixcloud.com http://flixcloud.com. Of course, it would be stupid for us to try to actually do the encoding in Rails. That's what C is for. But Rails makes a nice lightweight queueing/management platform that can work alongside of other tools. Each of your examples is a place where Rails isn't appropriate. But each example should be a multi-tier architecture, and Rails can happily cover one or more tier in each case.