Learn Elixir with a Rubyist (IV) – Types, Data Structures and Pattern Matching

Javascript is a very common language. Elixir is generally a better language, but less popular. If you're looking to get a job you could probably do either but there are probably more Javascript jobs. At the hobbyist level Node might be easier to pick up, especially if you know Javascript already.

I'm currently working in both. If we are just talking about them in terms of their respective merits, Elixir is my preference. It has a wonderful compiler, pipes allow for composable chains of logic, the Phoenix framework is wonderful for web development. Literally every interaction with it I've had has made me think "wow that's just a great example of excellent programming taste...". In terms of scaleablilty, I've heard stories of a single server able to handle millions of requests. Not personally been able to verify that (nothing I've done in the language has reached that kind of scale sadly...). Once you get used to pattern matching, you'll wonder how you ever lived without it. The community is amazing and supportive. The language creator Jose Valim has responded to my emails directly which is really cool.

With Node, you can cobble together pretty much everything I've described (except for maybe pattern matching) above but it's a bit of a kluge IMO. You can program functionally. And you can make yourself a kind of "compiler" via linting or perhaps by using Flow or Typescript. I've yet to find the experience fluid or pleasant. The language is just not designed for that stuff. ES6 is a huge improvement that said. And before you go thinking I am a node hater, I love JavaScript and use it all the time. I'm just painfully aware of its shortcomings because of how much I work with it.

My biggest issue with Elixir is that it's hard to set up a proper CI/Deployment pipeline. It CAN be done and I've done it but nothing "just works" like it does with Node. Try dockerizing a phoenix app or setting up a heroku instance to see what I mean. All of these things work but it's an obscure language so one needs to be more advanced to understand and address problems in that area.

To sum up: very excited about Elixir and hope it continues to grow. If I was starting a new project I would probably use it.

Elixir (well I use Erlang but it is close enough).

* I like the concurrency model better. Lightweight processes vs callbacks and futures. I find processes as concurrency units maps better to problems I had to solve. So there is less impedance mismatch. That makes a huge deal in a larger project. (eg.: a user request as an isolated process vs a chain of callbacks). OS design got this right years ago -- think how most modern popular operating systems represent concurrency - an isolated process.

* Safety & fault tolerance. Processes are isolated. So you can build very robust systems. That simply puts money in your pocket just due to ops costs. A non-critical / experimental part of backend is crashing at 4am and restarting? No, problem, keep sleeping. Rest of the service will stay up and you can fix it in the morning.

* Debuggability and inspection. BEAM VM comes with built in ability to debug, inspect and trace out of the box. That has saved so much time (and money) over the years.

* Hot code reload. This is a first class feature. We don't rely on it to do upgrades. But it proved invaluable to fix an issues or two for a high value customer without taking down the services. Or simply to add extra logging to monitor a pathological edge-case.

I'm working on both too, and one point that I faced was the Node 1.5GB RAM limit per node process (at least on Heroku https://devcenter.heroku.com/articles/node-concurrency - I know it can be worked around though, although not on Heroku), which can force you to run multiple processes (aka clustering) depending on your use cases (e.g. thousands of client websockets connections from the process, if you need to listen to a large number of e.g. Slack connections).

This can lead to a more complicated architecture than with Elixir, where a single Elixir process will be able to use more RAM & all the cores, too.

On the other hand, I love the dynamism of the Elixir ecosystem, but it's not yet as rich as Node's one, and it's still harder to find a proficient Elixir developer, than a Node one.

But personally yes: the fundations of Elixir are very, very strong, and I'm investing in it completely (in addition to Ruby & Node, which I already use).

All forward looking statements are guesses but... I see a strong movement toward Elixir from Ruby devs (and others, I'm not a Rubyist) and I expect Phoenix to be one of the main frameworks in the next few years. It's due to a combination of simplicity, history (erlang is old), and a change in the types of apps some of us are building. There will always be simple CRUD apps too but the demand for constant connectivity seems to be rising. IoT, desktop replacement apps, etc.

Edit: fixed typo referring to Elixir as a framework