I have been using Elixir for the past more than 2 years and got say that it has an awesome ecosystem for overall web development, I've been using and writing open source libraries and they are looking pretty solid as well. The company I work for also uses it as its main backend for the past almost 3 years and it has been working nicely since then. Hiring also got way easier, not only because of the existing developers using it already but also because the interest on it has increased.
I second that Elixir's ecosystem is exceptionally great for such a young language. I love working with it.
That said, I'd wager it can hardly be called a functional language. Sure, you can't write for loops, but every Elixir process encapsulates a little piece of mutable state. Elixir and its ecosystem allow and encourage you to have (very) many processes, and thus many global singleton-like pockets of mutable state. It's a powerful and pragmatic concept, it works very well, but it doesn't really feel very functional.
The most extreme example of this design philosophy is a Elixir standard library module called "Agent", which is just a cute name for "global mutable variable". When used with care it's a very handy tool but, well, functional? Nah :-)
While I don't disagree entirely, I find that Elixir is actually quite functional. Using processes for state as if they're objects is generally considered bad practice.
> But before starting, since this is going to be a long article, I want to immediately share my main points:
> Use functions and modules to separate thought concerns.
> Use processes to separate runtime concerns.
> Do not use processes (not even agents) to separate thought concerns.
> The construct “thought concern” here refers to ideas which exist in our mind, such as order, order item, and product for example. If those concepts are more complex, it’s worth implementing them in separate modules and functions to separate different concerns and keep each part of our code focused and concise.
> Using processes (e.g. agents) for this is a mistake I see people make frequently. Such approach essentially sidesteps the functional part of Elixir, and instead attempts to simulate objects with processes.
