This chapter highlights that software developers are smart, and some of them have developed techniques that will help us create a lot more than 20 minutes' worth of code in a day, and with vastly increased aesthetic satisfaction. The chapter talks about language features and further highlights that JavaScript is single‐threaded. With the advent of Single‐Page Applications, node.js, and other ways of making JavaScript shoulder the burdens of larger and larger systems on both client and server, the best JavaScript developers get serious about trimming those channels of communication to a bare minimum. JavaScript, with the extraordinary flexibility of pervasive duck‐typing, lets you write a little code that can do a lot. The chapter explains the SOLID principles, which include: the single responsibility principle, open/closed principle, Liskov substitution principle, interface segregation principle and the dependency inversion principle.