Testing and refactoring go hand in hand. Refactoring is all about improving code without changing its behavior. Testing is all about making sure you don't change the behavior while you are improving the code.
ZURB's Foundation is a front-end for quickly building applications and prototypes. It is similar to Twitter Bootstrap but uses Sass instead of LESS. Here you will learn the basics of the grid system, navigation, tooltips and more.
Caching at a low level is a great option when the view is too dynamic to cache and you need something flexible that can work anywhere in the application. Here I show a variety of ways to use Rails.cache with Active Record.
Here I demonstrate how to perform bulk API operations though a single request using Rack middleware. This is great if you need to trigger multiple actions at once such as if the user goes offline.