Don’t write GenServers. Use them.
As in, like… never write your own GenServer? Are you talking from scratch? Or literally never type use GenServer and find a lib that does what you’re looking to do?
Sorry to pick apart your succinct point, but as a n00b I’m really curious here.
I wish I could write as succinctly as this 
Instead of my ramble I wish I had just written this because this is exactly how I feel too.
I wouldn’t say never, but they are really hard to get right, so I’d recommend waiting a bit until you write GenServers, like 1 year or so. You should be using GenServers that other people have written with a clear api and usage examples (like liveview or broadway). There are a few cases (like a game with state) that are exceptions
I had only this weekend documented the Elixir related books that I have read (or intend to read):
I found Elixir a few years ago (oddly while browsing a bookshop). It seemed to be a more accessible version of Erlang.
Now it’s my goto language for small utilities.
I spend some time each day mentoring on exercism.io to keep my hand in.
I have been toying with Elixir time to time for some years now, but I think this year will be finally the year that I will go full ahead and put some of my ideas in practice and release them for the world to see, and all this in Elixir 
All the knowledge I am acquiring in this process will be collected under Phoenix360 project:
bash bin/deploy.sh from your PC to build the Docker release, deploy it to the target, and start it on the target. All this without using any tooling like Ansible, Puppet or Chef.
.edu email. It became my new Bible.
Answers in order of questions:
New to Elixir and Erlang as of this past year. I saw a talk that I feel terrible for not remembering the name of, but the speaker was talking about how discovering Elixir and Phoenix changed his whole perspective on programming, web dev in particular. Quarantine hit and I decided that I would spend the whole thing just absorbing the world of Elixir, learning about Erlang and what was/is so special about it. Never looked back.
I originally landed on that talk while looking for alternatives to plain JS/React. I certainly found what I was looking for in Elixir and Phoenix.
I had no experience with functional programming or anything non-OO, so I have found it both immensely challenging and hugely rewarding. Every time I break through another hazard on the road to learning Elixir, I’m generally rewarded with something that feels like a super power.
I’ll be using it primarily to develop a sales and information platform for a company in an industry full of people who are VERY tech-phobic.
I don’t think I find any of it easy, but it’s ALL rewarding. The hardest thing for me is seeing the plumbing of a piece of software. I guess I’m really looking for a purpose-built IDE that has shockingly good debug tools. I’ve heard IntelliJ is a favorite, but the plugin was a little wonky last time I used it.
I think a better IDE story is missing as stated above, but this is almost certainly because I haven’t learned to fully utilize debugging tools beyond IO.inspecting everything to within an inch of its life, lol.
Hope this is useful!
I was brought by boredom in Ruby.
Stockholm syndrome is keeping me there 
I started to see more that closures == objects (in Java/Ruby sense).
FP and FP. Additionally the idea that the VM is the OS you are running your applications is quite nice (BEAM is an OS).
Integration between Erlang and Elixir. The Mix (Elixir) and Rebar3 (all other BEAM languages) is quite irritating.
Binary pattern matching and new socket module.
receive is blocking and (almost) “free” in regards to CPU time.
Well I for one have really enjoyed reading everyone’s input, especially the longer posts! 
And it’s awesome seeing so much excitement from some of our newbies (props to you all!!) and in fact it has made me want to hurry up and get a couple of Phoenix pet projects done that I’ve been meaning to do for a while …you may not realise it but even as a newbie all your enthusiasm and excitement is actually helping keep the passion alive for some of us older dogs, too. So thank you! 
That’s awesome to hear! We have a great bunch here and it’s brilliant seeing more and more cool people like you join everyday 
Absolutely!
Thank you everyone who has taken the time to respond to this thread - these types of threads are some of my favourite 
Wanted to make a very slow Ruby on Rails reporting system faster. I already started learning Elixir some months ago and looked for an opportunity to utilize it in real business context. I eventually reduced those Ruby on Rails reports times from 3.5-4.0h to 5-8 minutes. It was a huge success!
Elixir did very naturally fit into such an ETL-like data processing pipeline. I respect it ever since.
C/C++, Java, Ruby, PHP, JS, Golang. Then Elixir and then Rust. I am only sticking to these two lately.
The language and the basic tooling themselves are absolutely excellent. There aren’t many drawbacks to find.
I believe the next phase for Elixir would be to commoditize parts of web dev in general – like having a tool actually analyzing and “understanding” your Phoenix code and allowing you to seamlessly move it around (which goes beyond simple refactorings). That might prove to be impossible however.
Erlang’s BEAM lends itself excellently to anything that needs to work in parallel. Even fantastic languages with dead-serious hardcore (and experienced!) fanbase like Rust still can’t catch up to OTP’s guarantees. They are inching closer, though!
If your project is NOT a CLI program or any sort of a server that needs every last bit of CPU power per watt – then it is very likely good fit for Elixir. We live in a world where CPU cores increase and CPU frequency hasn’t moved for a long time and likely will not anytime soon. Use technologies that utilize all CPU cores.
To me that’s Elixir’s strongest benefit. Its fantastic meta-programming is a close second.
Piping is both easy and makes code readable. Love it, always will.
Reducing compilation times has been a challenge. Analyzing dependency graphs has been getting easier (with Elixir 1.11) but I’d appreciate seeing a tool that can give you direct and immediate insights: “module X seems to depends on 100+ files, extracting this function to another module will help”. A note for future improvement.
Dialyzer and typespecs remain pain in the rear to this day. But I don’t think that will ever change. It’s more likely that Facebook will make statically typed Erlang, or languages like Caramel and Gleam will gain prominence (they are statically typed as well). I don’t think Erlang’s legacy tooling can be expected to change at this point.
More commoditization of, well, anything.
compat package that makes sure that all Elixir projects can use upcoming API like e.g. Enum.product (coming in Elixir 1.12) even if they are at Elixir 1.6 at the moment.I am sure I am forgetting at least 5 more but hey, can’t keep them in my head all the time.
I could answer the other questions but this comment is too long already.