Why Your Cached JavaScript Is Still Slow and Incurs Performance Overhead

Joe Liccini discusses the overhead associated with loading JavaScript, even if it’s loaded from Browser Cache.

Caching assets is a fantastic way to optimize the network overhead of your web application, there is still plenty of computational overhead associated with cached JavaScript.

He recommends continuous measuring and profiling to identify this overhead. Consider techniques that utilize static HTML and CSS, rather than runtime client JavaScript compute. Aggressively reduce the size of JavaScript bundles to minimize client computational overhead. Analyze and measure codepath efficiency of required JavaScript to minimize the total amount of client compute and allow the browser to present frames efficiently.

Source: Why Your Cached JavaScript Is Still Slow and Incurs Performance Overhead