Users want well thought workflows and responsive interfaces.
They want to use your app and get that feeling that it's sharp and snappy.
They also want it to work everywhere.
Oh, yeah, and the more geekies will surely want to connect it with another amazing platform (or that wicked script on their sh-dev-shed) that does that little thing that makes their life complete and which they would love you for.
This talk is about building real applications with proper UX, helping you understand where you should be drawing the line between what Ruby should be doing and when something like Backbone or any other frontend structure would be a perfect fit so that your users <3 you for such an unbelievable experience.
It will also push you towards building well structured APIs from day one so that you can easily interconnect with other systems afterwards, grow and scale.
Yes, this talk is about getting the right structure in and using technologies that fit better to make your users happy. At the end of the day, it's all bout making things right.
It's a win win :)