If you are a JavaScript developer interested in learning functional programming, looking for the quantum leap toward mastering the JavaScript language, or just want to become a better programmer in general, then this book is ideal for you. This guide is aimed at programmers, involved in developing reactive frontend apps, server-side apps that wrangle with reliability and concurrency, and everything in between. JavaScript is a high-level, dynamic, untyped, lightweight, and interpreted programming language, and functional programming is a style that emphasizes and enables smarter code, minimizing complexity and increasing modularity. This course will take you on a journey that shows how functional programming, when combined with other techniques, makes JavaScript programming more efficient. The first module stresses the practical aspects of JavaScript development, including everything that a modern JavaScript project will need. The second module explores how design patterns can help you improve and organize your JavaScript code. You'll get to grips with creational, structural, and behavioral patterns as you discover how to put them to work in different scenarios. The third module will help you to write real-world applications by utilizing a wide range of functional techniques and styles. It explores the core concepts of functional programming common to all functional languages, with examples of their use in JavaScript.