Gain insights into building scalable backend applications with Elixir, OTP, and Phoenix. Learn about persistent connections via Phoenix Channels, and explore distinct, decoupled application layers.

Functional Web Development with  Elixir, OTP and Phoenix by The Pragmatic Programmer_ .png

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Elixir and OTP provide exceptional tools to build rock-solid backend applications that scale. In this course, you’ll build a web application in a radically different way, with a backend that holds application state. You’ll use persistent Phoenix Channel connections instead of HTTP’s request-response, and create the full application in distinct, decoupled layers.

In Part 1, you’ll start by building the business logic as a separate application, without Phoenix. You’ll model the application domain with Elixir functions and simple data structures.

In Part 2, you’ll add in the GenServer Behaviour to make managing in-memory state a breeze. 

In Part 3, you’ll build a web interface with Phoenix where you’ll use Phoenix Channels to establish persistent connections between the stateful server and a stateful front-end client.

Needless to say, you’re going to love this way of building web apps!

Functional Web Development with Elixir, OTP and Phoenix

## The history of web development

In the early days of web development, well before web frameworks existed, a Perl script in an Apache `cgi-bin` directory and a couple of static HTML files were all we needed.



In the intervening years, web frameworks for both the front and back-ends have become ubiquitous. This has been fantastic for the industry. The productivity gains are undeniable. The consistency across applications allows us to onboard new developers more quickly.

Despite the gains, there are also disadvantages. The way we’re commonly taught to use frameworks causes extremely tight coupling between the framework components and our business logic. Databases have gone from simply augmenting storage to dominating the way we model application domains.

## The importance of Elixir and Phoenix 

Most people use Elixir and Phoenix for the performance, and there’s no question that the performance is fantastic. 

Elixir and Phoenix provide solid solutions to these long-standing problems without sacrificing gains. Elixir is especially useful because of the access it gives us to **#key# OTP: Open Telecom Platform #key#**. 

Elixir and Phoenix also open up new possibilities, bringing back some of the benefits of statefulness that we’ve lost with the rise of HTTP.

Throughout this course, we’ll build a web application together that shows what Elixir, OTP, and Phoenix can really do when used well together. Most of all, however, we’ll have fun. We'll learn things you can use to make the code for our day job or side projects more beautiful, easier to maintain, and a joy to work on.

# The history of web development

In the early days of web development, well before web frameworks existed, a Perl script in an Apache `cgi-bin` directory and a couple of static HTML files were all we needed.



# The importance of Elixir and Phoenix 

Most people use Elixir and Phoenix for the performance, and there’s no question that the performance is fantastic. 

Get introduced to Elixir and Phoenix and find out who this course is intended for.

Introduction

Mapping Our Route

Model Data and Behavior

Working of State Machines

Add OTP for Concurrency and Fault Tolerance

Process Supervision for Recovery

Generate a New Web Interface with Phoenix

Create Persistent Connections with Phoenix Channels

Appendix

Background

The history of web development

The importance of Elixir and Phoenix