Introduction to Phoenix

Phoenix is a web framework that sits on top of the Elixir programming language, much in the same way that Rails sits atop Ruby or Express sits atop Node and JavaScript. There are a few areas where Phoenix shares a lot of the same core ideas and beliefs of other frameworks and areas where Phoenix differs pretty heavily.

Phoenix is very much designed to be a standard Elixir application and thus abides by the same rules and the same principles, but also encompasses all of the same things that make Elixir so great to work with! In my mind, the first and biggest thing that Phoenix gets via Elixir is first-class and dead-simple concurrency support. Writing code that performs and scales well on multiple core machines (that is, basically every single computer out there nowadays) is a breeze, and when you're just starting out building your Phoenix application, you won’t even have to think about it. It isn't until you start diving more heavily into the more advanced topics, such as OTP, GenServers, and Async Tasks, where you really need to start thinking deeply about your concurrency models and how everything fits together.

Phoenix also benefits very heavily from being based on a functional immutable language. Large codebases remain very simple to reason with, and the fear of introducing significant breaking changes because of a mutation deeply-nested in your code is now a thing of the past! If you're coming from a language where you've built a complex application and a simple change ends up breaking everything, this should be a breath of fresh air to you. I referenced this in one of my earlier examples, but when you actually see it in action and understand why it works the way it does, trust me, you won't want to go back to the old ways of building applications!

Before we do anything else, let's talk briefly about how to actually install Phoenix so that you can get started on working with it as soon as possible. The best (and most up-to-date) instructions can be found on the Phoenix framework website (https://phoenixframework.org), but just in case, here you are. Please note that the following instructions assume you already have Elixir installed.