Responsive & Fast

Chapter 6. RESS and Adaptive Delivery

At the beginning of this book, we described two mobile web strategies: dedicated websites (mdot) and Responsive Web Design. The mdot approach fell short when trying to handle the diversity of devices and sharing links between them, but did better in avoiding excess download. The RWD approach was better at adapting, but often resulted in bloat, hindering performance. Each approach has its pros and cons, which begs the question—is there a way to combine the best of both worlds?

Such an approach is referred to as RESS (REsponsive + Server Side components), a term coined by Luke Wrobleski. It’s a slight deviation from “pure” RWD, where the decisions were all made on the client side, but this deviation allows for substantial performance improvements.

Adaptive Delivery

Before we dig into RESS, we should mention a new and increasingly popular mobile strategy called Adaptive Delivery.

Adaptive Delivery means having dedicated websites, just like we did with the mdot approach, but serves all websites over the same URL. The use of a single URL alleviates some of the issues with dedicated websites, such as improving link sharing, removing redirects, and improving SEO. These benefits make it a compelling alternative to having separate dedicated sites.

Implementing Adaptive Delivery is often done by using a smart routing entity that sits at the front of your website’s delivery, such as a CDN or a load balancer. The service determines the incoming client just like ...