Chapter 3. Handling Web Requests

A web application is an application that responds to requests over the Web. Ideally, a web application is an application that responds to web requests quickly, doing the smallest amount of work required to return a response. Most web apps serve users interacting with the application in real time, and a fast response means less time the user is waiting for an action to be completed or information to be displayed. With user-facing web apps, milliseconds matter.

A less obvious advantage to an app that responds quickly is that it’s easier to scale. The less work the app does in response to a request, the more efficiently those requests can be distributed across multiple servers. It’s like scheduling meetings on a busy day: the shorter the meeting, the more likely you’ll be able to fit it in.