People have been trying to make websites faster ever since the browser was invented, and in that time, the web performance industry has made a vast number of advancements, each addressing specific performance bottlenecks. Thus, as the web has evolved, so have the methods for measuring and improving its performance. This presentation covers: ● A brief overview of the evolution of performance on the internet ● How to select and collect the proper metrics to define client-side performance ● Best practices for performance tuning modern web applications