[haolez]

Slightly off-topic, but are there teams using Erlang instead of Elixir for application development?

I'm planning on getting into this ecosystem and I'm considering if it's worth it also becoming an expert on Erlang beyond understanding OTP's internals.

[xlii]

For serious apps it's impossible to escape reading Erlang or Erlang documentation. Many functions and libraries simply aren't available for Elixir or are partial (see `opentelemetry_*` family as an example). Deep debugging is almost exclusively done with Erlang functions.

I'd even say that the more serious/critical application becomes the more weight shifts toward Erlang. Personally I'd go with Erlang-first, but only because I've accumulated thousands paper cuts from Elixir.

For starters Elixir has much more palatable syntax, though.

[ch4s3]

> For serious apps it's impossible to escape reading Erlang or Erlang documentation

Erlang documentation yes, but I VERY RARELY look at Erlang code. The only times I've really done it have been fiddling with an ODBC driver issue, which isn't really supported anymore by OTP, a crash dump maybe twice, and writing a dialyzer wrapper. I've been building elixir systems for over 10 years, and use OTP heavily,

[haolez]

But beyond syntax, how does the tooling compare? It seems that Mix is very convenient and feels like similar tools in other languages. I'd imagine that Erlang doesn't have an equivalent.

[bartblast]

It depends on what you're doing. I've been in Elixir web dev for about 7 years and never really needed to write or understand Erlang, outside of my work on Hologram. That said, Erlang is always there under the surface - it "leaks" into Elixir in places if you look at the stdlib, and understanding it gives you a better mental model of the whole platform. I'd say you don't need it on a daily basis for most Elixir work, but the runtime and OTP are incredible pieces of engineering, and getting to know Erlang better will only make you stronger in this ecosystem.

[atonse]

Just wanted to echo that my experience is almost identical (production elixir/phoenix for 10 years), and also very rarely touch erlang. But it does leak in every now and then.

And it'll feel less intimidating once you code in elixir, but I still find it more cryptic and less approachable the 3-4 times I've had to splunk into erlang to debug something in the last decade.

[GCUMstlyHarmls]

It's very easy to call Erlang from Elixir,

    value = :erlang.function(a, b, c)

So with that in mind, you can just learn Elixir, use Erlang where you need it for some libraries. Elixir is IMO much nicer to learn, write and use. I think it is worth learning a bit about the underlying systems but I've never felt like I should have put in 10 erlang-only projects before writing larger elixir stuff.

[ihumanable]

Just to emphasize this as someone that's worked in Elixir professionally for a decade now.

It really is that easy. The interoperability between Erlang and Elixir is fantastic and the communities get along well. There has been a long time push from many of the thought leaders that BEAM (the VM that Erlang and Elixir run on) should be a community regardless of language. That way we can share resources.

When I first learned Elixir I spent all my time in Elixir. Erlang has a lot of nice libraries though, so it wasn't uncommon back when I started to reach for one.

It was a pretty gentle learning curve, you can write Elixir with no knowledge of Erlang at all. You can consume Erlang libraries from Elixir with no knowledge of Erlang at all. Then if you are like me, you are curious about how something works and you go read some library code and it's a bit odd but you can mostly get the gist of it. Then over time reading Erlang is easy enough, the prolog inspired syntax is the hardest hurdle to get over, but then you realize how much Erlang and Elixir have in common.