Phoenix – First Impressions

For the past decade, my primary tool for building web apps has been Ruby on Rails. Using such a toolset helps me rapidly build apps with a predictable structure and the means to manage the database schema.

Of course, there are trade-offs when such things are used, but discussing those is out of scope of this post. Instead, I hope to focus on some positives that they provide.

In my opinion, web frameworks show their worth in the early stages of app development and the mid term when there is some developer churn. It aids both Current Developer (present day maintainers) and Future Developer (eventual project maintainers) by providing some safe assumptions about where things are and the general app flow.

Enter Phoenix…

Recently, I began exploring Elixir and shared my first impressions [1]. Developing web apps in a manner similar to Rails naturally points to the Phoenix Framework, since the core team is influenced by it [2].

Rather than setting expectations for specific things, I jumped in with one thing in mind: hoping to find that I can remain as productive with Phoenix as I can with Rails.

How Did I Learn?

To get familiar with the framework, I followed the Phoenix guides provided on the main site. It hits all of the highlights for typical project management including resource generation, database management, and app testing.

Here are my take aways…

Thumbs Up!

A few of my favorite things…

Schema in the Model

In Active Record with Rails, details about the schema are “hidden knowledge” from the data model; the information is available in a separate database schema file. In Ecto, defining the schema inside the model exposes valuable information for Future Developer, providing the underlying makeup of the data model in line. Awesome!

Data Repo

Rather than executing any activity with the database directly through the data model, Ecto uses separate Repo modules to manage that activity. This is nice since it keeps the model isolated from database connectivity concerns, and instead leaves them focused strictly on data modeling.


Baked in support for channels allows any type of client to subscribe to Phoenix apps for “real time” data. With the BEAM managing large numbers of concurrent connections, the confidence level for a stable solution should be high.


This spec provides a good way to isolate behavior for reuse elsewhere that could be painless to test. Win!


Surprisingly, I encountered one thing that bothered me, but it is a big one.

Node.js Dependency

I was very disappointed to learn that I need Node.js for the default static asset manager, Brunch. To be fair, this dependency is optional, and any build tool can be used. However, from what I have seen, the default tends to be favored in the wild by frameworks.


Do I feel that I can be productive with Phoenix? Yes! I believe that after getting more comfortable with the tooling, and Elixir in general, that the development pace could be maintained.

Now I am eager to put it to work to see it in action!


  1. Elixir – First Impressions
  2. Phoenix is not Rails
Phoenix – First Impressions

Elixir – First Impressions

I have been an Erlang/OTP enthusiast for a few years. Considering that most of my day job is spent writing web apps, the platform’s focus on providing highly available, distributed, fault-tolerant systems using immutable data is very appealing.

But what about Elixir?

Considering that my main language is Ruby, one would think that I am drawn to the familiar syntax. However, I felt comfortable enough in Erlang/OTP that the Elixir syntax felt unnecessary.

Why Now?

Curiosity finally got the better of me! Two things in particular finally convinced me to take a closer look:

  1. Tooling – What is working with Mix like? How easy is it to feel productive?
  2. To the BEAM!Erlang/OTP adoption seems to be hindered by the syntax. If Elixir is more comfortable to a wider audience and it still compiles for use in the BEAM, so be it!

How Did I Learn?

My introduction was by following the the Elixir tutorial [1] provided on the main site. It is a well written guide with many examples introducing newcomers to the syntax, pattern matching, inter-process communication, and OTP libraries. It also uses Mix throughout the guide running code, tests, and generating applications.

The tutorial covers many topics for newcomers, and I encourage you to check it out!

Here are some things that I stood out to me along with some things that I am less enthusiastic about…

Thumbs Up!

While this is not a complete list, these things stood out to me.

Document Testing

This is a powerful feature. It encourages quality examples in the documentation itself while also providing test scenarios, verifying that the examples are sane. I believe that this is a really good way to communicate how a function is expected to be used, leaving the edge cases for unit tests.


The tooling is easy to use and involved in many regular tasks. It drives running tests, code compilation, app loads into Interactive Elixir, app dependency management, and new app generation.

Umbrella Projects

Speaking of app generation, umbrella projects are nice! They can be used to wrap multiple small and focused apps, simplifying the task of grouping multiple apps to form one complete unit.


I am not sure that would list these if I had not already learned Erlang/OTP, but I did (with this [2]), so here we go!

Rebinding of Variables

Erlang/OTP does not permit reusing variable names*, yet Elixir does. To me, this discourages immutable data from staying in mind during development.

* Technically it is possible to reuse variables in an Erlang/OTP shell if you flush out the current process’ knowledge of them, but it is not possible in a running application [3].

Lowercase Variables and Functions

Erlang/OTP forces variables to be uppercase. When reading code, it makes it very easy to identify by casing alone what are variables that store values and what things provide values (functions, records, etc).

Elixir, however, chooses to make modules uppercase, allowing variables and functions to both be lower case. This is familiar to Ruby developers, but the opposite of what Erlang/OTP developers are used to seeing.


I walked away with a good impression of the tooling:

  • Elixir places a priority on documenting and testing code
  • The design of small and focused apps is encouraged
  • Mix makes it easy to bundle them up with umbrella projects

These things help developers build nicely designed Erlang/OTP apps.

Soon, I am going to check out the Phoenix Framework to explore its use developing web apps! [4]


  1. Elixir – Getting Started – Introduction
  2. Learn You Some Erlang for Great Good!
  3. Invariable Variables
  4. Phoenix – First Impressions


Elixir – First Impressions