From what we have seen and built so far, we can all agree that AngularJS is insanely fast. For standard size views, we rarely see any performance bottlenecks. But many views start small and then grow over time. And sometimes the requirement dictates we build large pages/views with a sizable amount of HTML and data. In such a case, there are things that we need to keep in mind to provide an optimal user experience.
Take any framework and the performance discussion on the framework always requires one to understand the internal working of the framework. When it comes to Angular, we need to understand how Angular detects model changes. What are watches? What is a digest cycle? What roles do scope objects play? Without a conceptual understanding of these subjects, any performance guidance is merely a checklist that we follow without understanding the why part.
We have covered concepts behind the digest cycle and dirty checking in Chapter 3, More AngularJS Goodness for 7 Minute Workout...