Summary
We now have a better understanding of why JavaScript is increasingly becoming a functional language and how this programming paradigm can be a vector for performance. We have learned how replacing overly complex code with simplified functional versions and how using immutability and tail-call optimization can help make JavaScript more efficient. We also got a quick glimpse of the upcoming features of the JavaScript language.
In the next chapter, we will have a look at a few projects that have went along with Google's Faster Web initiative over the years and we will see how it is possible to combine these technologies in order to boost overall web server performance.