A microservice architecture shifts around complexity. Instead of having a single very complicated system, there are a bunch of simple services with complicated interactions. Our goal is to make sure that complexity stays in check and within boundaries. Security is really hard to get right. There are countless ways to break into an application. Node.js is no different. In this section, we are going to look at the techniques to prevent security vulnerabilities. This section is meant to act as a basic checklist to ensure that our microservice addresses some of the biggest security threats. So, let's get started.