I have this arbitrary career goal: I want to make a back end that serves millions of requests and does it blazingly fast. Having been a Rails developer for most of my programming career, I’ve been branching out to learn a new language. As you can see from my past posts, I was dabbling with Golang. I even wrote http://gruuub.com with it. It’s fast for sure, but I wanted to see what else was out there.

Enter Elixir and Phoenix. Elixir is a new language built off of Erlang. Phoenix is a web framework for Elixir. And it’s fast. Lighting fast. Serve pages in microseconds fast.

First Impressions

Functional programming is weird. I tried to do an exercism.io in Elixir and utterly failed. After that, I decided that some reading was in order. I bought Programming Elixir and started reading it, and that helped a ton. I could actually write some Elixir code after that. Nice. On to making a web app!

Phoenix is an MVC framework heavily inspired by Rails. In fact, I found that a lot of features of Rails are already present in Phoenix. Migrations, the awesome router we all know and love (albeit slightly different), even the flash. It’s a full-featured web framework for sure. Getting it up and running equally simple. Install Elixir, install Phoenix, generate an app, create your database, and run mix phoenix.server. Pretty simple.

A Test Drive

After I commited to a hack-a-thon that Quick Left (my employer) was hosting, I decided to use Phoenix for the back end of my team’s web app. Why not? I had yet to use it for something real and I didn’t really care about winning. So I used it. The result? I was surprisingly productive. We only had about 2 - 3 hours to write something. In that time, I spun up a web server with a couple JSON API endpoints that served (mocked) data for the JavaScript front-end.

I tried utilizing the database, but failed. I created 3 models with migrations, but ultimately failed to implement the controller actions for them correctly, so I scrapped it and just used mock data. But holy Batman, making those models and migrations was dead-simple because of the generators.


If I were 1) using the database and 2) serving from a real server (not localhost), I’m guessing this would be slower. But I don’t think it would slow down that much. Here’s the server log with response times:

[info] GET /api/shops
[info] Sent 200 in 756µs
[info] GET /api/shops
[info] Sent 200 in 774µs
[info] GET /api/shops
[info] Sent 200 in 752µs
[info] GET /api/shops/1
[info] Sent 200 in 920µs

Behold, MICROSECONDS. Have you ever seen that µ symbol in a server log before? My team mate had to Google it. Yeah…lightning fast.


Phoenix is lighting fast but is still just as productive as Rails. More to come when I get something working in production. You should also hire QuickLeft to make something with Elixir so I can get paid to work with it more.