On: Scalable Web Architectures: Common Patterns and Approaches

[lsb]

Yes, this is why you load images and CSS from a CDN, and you can do JSON+callbacks instead of Ajax onto a big app server somewhere. (There's a gem for Rack, if you're on Ruby, to automatically handle the parenthesization.)

[wanderingmarker → lsb]

What do you mean by JSON+callbacks?

[lsb → wanderingmarker]

You promote data to code.

JSON is usually a data format, like {result: 42}. If you wrap that in callback({result: 42}), that's executable javascript code.

Including script tags on your pags via JS, like how the Delicious API / Flickr API / Google Translate & whatnot APIs, all rely on this. Check out http://developer.yahoo.com/common/json.html#callbackparam