Node.js is a fast-growing platform for building server applications using javascript. Now that it is being more widely used in production settings, Node applications will start to be specifically targeted for security vulnerabilities. Protecting your users will require an understanding of attack vectors unique to Node, as well as shared with other web applications. To secure Node.js applications, well start by helping you delve into the building blocks that make up typical Node applications. By understanding all the layers that you are building on top of, you can write code defensively and securely. In doing so, you will be able to protect your user's data and your infrastructure, while still using the rock-star technology behind Node.js. Teaching you how to secure your Node applications by learning about each of the layers you will be building on top of; starting with javascript itself, then the Node platform, and finally the npm module ecosystem. By starting with javascript, you will learn what to avoid and what to embrace. Next, we will explain the Node platform, including its unique architecture and core modules, so you know how things work under the hood. Finally, we will introduce the rich ecosystem of npm modules, including modules to help you solve the common security problems you might face. Through our handy tutorials, you will be able to write secure Node.js applications, ones that will remain online under pressure and be able to weather the most common attacks that face web applications today.