I think it’s more like if you are making a open source library for Erlang ecosystem that doesn’t need other Elixir libraries or features then it might make more sense to use Erlang. For other kind of projects it doesn’t really matter. From what I understand Gleam language also has good interoperability story but that language might not yet be mature enough.
wanton7
AstonJ
Well the reason I came to Elixir is because I want to use it to build a social network 
As many have said in the thread, WhatsApp is already powered by Erlang, and is a technological feat - you’ll see in the article linked to by @toronja that their app has 900M users and they did it with a team of just 50. That’s incredible - and goes to show that Elixir/Erlang will be able to get you to that sort of scale much easier and quicker than what might be possible in other systems.
With regards to Elixir or Erlang - Elixir runs on the Erlang VM, so all the power of Erlang is available to Elixir. The differences are in things like tools/libraries/frameworks etc. Erlang has frameworks like Zotonic, Nitrogen, Nova, Chicago Boss and Elixir has Phoenix (as the community has preferred to stick to one) so look at the syntax and tools of each and just go with which you prefer. Ultimately, in my eyes, we’re all Erlangers in some shape or form at the end of the day 
5
robinhilliard
@alphanumeric If you’re interested in more detail about the similarity of BEAM byte code regardless of source language I did a presentation at Elixir Sydney that compares the BEAM byte code generated by an Elixir and Lisp Flavoured Erlang implementation of the Exercism ISBN verifier: https://youtu.be/R0wSbza74XA?t=1860. You can find out even more at my source for the presentation: GitHub - happi/theBeamBook: A description of the Erlang Runtime System ERTS and the virtual Machine BEAM. · GitHub.
5
alphanumeric
Exadra37
Doesn’t sit on top, it runs on the same Virtual Machine, the BEAM.
Erlang code is compiled to run on the BEAM and Elixir code is also compiled to run on the BEAM.
As already pointed out Discord it’s a good example of running Elixir at scale:
Now if at some point you need to squeeze more performance then you can call Rust from Elixir as Discord does nowadays for some bits of their app that are very performance sensitive:
5
wanton7
If Elixir sits on top of Erlang, wouldnt that make Elixir slower than erlang?
No it won’t be slower it doesn’t sit “top” of Erlang it compiles to Erlang abstract format. Good comparison is TypeScript that compiles to JavaScript and TypeScript isn’t slower than JavaScript. You could also think it as similar to Kotlin for Java VM that compiles to same Java bytecode like Java itself does. Kotlin is not slower and can use Java libraries similar how Elixir can use Erlang libraries.
2
thojanssens1
I didn’t understand this argument as WhatsApp has billion of users and server is written in Erlang ?
2
dmitriid
Any chat is a stupidly simple problem that is very hard to scale properly. The entirety of a chat system is: get a message, broadcast it to all participants. That’s it. Proper social networks like Facebook are more complex, of course. That said:
WhatsApp is built on Erlang. Erlang VM is what Elixir runs on, so yes, you can use Elixir for that.
Discord uses Elixir.
Facebook is C++, and PHP (most likely not a lot of it now), and at some time Erlang.
Instagram is Python.
EVE Online, one of the largest MMOs in the world, is Python.
Apple’s push notifications are Java.
Spotify is Java and Python.
Literally any language can be used to build what you need. Elixir/Erlang give you better basic building blocks than other languages, but you still need to know what to do.
3
dimitarvp
I am aware and it’s a very classic that many people give to advocate for Erlang/Elixir – myself included. This is not bashing the BEAM.
I am simply assuming that from a certain scale and on the throughput might be a problem, that’s all.
0
HappyBee
Hi AstonJ, did you build the social networking app, yet? I’ve a similar idea to build an app for doctors appointment.. I’m right now learning to work with absinthe but I’m stuck at authenticating an user on web and mobile app 
1