We do at http://cargosense.com/ and it's been an excellent choice. Elixir is totally compatible with existing erlang code, which means we've been able to leverage erlang libraries, OTP supervision practices and so without any trouble at all, while still getting excellent macros, protocols and so forth. I'm a particularly big fan of Elixir's lazy collections called Streams, and the ability to build your own. We've written a library for interacting with DynamoDB and Amazon Kinesis that uses these to handle the pagination of those resources behind the scenes so that when you're using the library you can just treat the resource as an ordinary collection and take as many as you like.
We're using the Phoenix framework http://www.phoenixframework.org/ as a backend for a web app written in Angular, and also as part of a data publication service. Phoenix makes a couple of great design choices influenced by its erlang heritage. Most notably it is really just one of the erlang "applications" you run, so it doesn't dominate or dictate the rest of your project structure. You can easily integrate it as just the web component of an application that has behind the scenes data processing or whatever else it is you'd want to do.
The only gotcha we've run into so far is that a lot of erlang libraries expect strings for configuration text (list of chars) whereas the convention in Elixir is to use binaries.This hasn't resulted in any real issues though, just a perplexed minute from time to time.
If you have any particular questions I'd be happy to try to answer them.
We're using the Phoenix framework http://www.phoenixframework.org/ as a backend for a web app written in Angular, and also as part of a data publication service. Phoenix makes a couple of great design choices influenced by its erlang heritage. Most notably it is really just one of the erlang "applications" you run, so it doesn't dominate or dictate the rest of your project structure. You can easily integrate it as just the web component of an application that has behind the scenes data processing or whatever else it is you'd want to do.
The only gotcha we've run into so far is that a lot of erlang libraries expect strings for configuration text (list of chars) whereas the convention in Elixir is to use binaries.This hasn't resulted in any real issues though, just a perplexed minute from time to time.
If you have any particular questions I'd be happy to try to answer them.