My Elixir learning journal

Chat / Discussions
1

This is the start of my Elixir learning journal/journey. I plan to share my journey in this thread and am open to all feedback, constructive criticism, and questions from people of all experience levels.

I’m a former full-stack Rails dev with FP experience (Scheme/Lisp via SICP was a wonderful introduction to the FP paradigm), but it’s been a while :sweat_smile:

My short-term plan is to complete a couple of online courses and read through several books as I get to know the ecosystem, and to hopefully start building cool things along the way. I’m particularly interested in leveraging massive concurrency and fault tolerance (to name just a couple of cool things) as it pertains to multi-agent orchestration and task management/decomposition systems for AI-powered software development. I’ve shared this in a couple other threads, but @chrismccord ‘s keynote at ElixirConf US 2025 has been particularly inspiring to me.

The courses I’m currently taking are:

  1. PragDave’s Elixir for Programmers, 2nd Edition and
  2. The Pragmatic Studio’s Elixir & OTP and Full-Stack Phoenix

And the books I’ve purchased so far are: (and will read possibly in this order, but am open to feedback)

    • Programming Elixir ≥ 1.6 + Elixir in Action + Introducing Elixir
    • Learn Functional Programming with Elixir (not yet shipped)
    • Adopting Elixir
    • Testing Elixir
    • Functional Web Development with Elixir, OTP, and Phoenix
    • Programming Ecto
    • Designing for Scalability with Erlang/OTP
    • Ash Framework

My short-term goal is to complete both courses and all introductory Elixir books by the new year, and my stretch goal is to complete these before I’m back from Thanksgiving holidays in early December. I’d really love to be able to build with Elixir/OTP + Phoenix by the new year. I’m also super interested in the DDD aspects of Ash Framework, but I wouldn’t be surprised if it takes me a few months before I’m ready to add that to the stack. We’ll see!

So far I’ve completed about 25% of both PragDave’s course and Elixir & OTP. They’ve both been very enjoyable so far but I’ve been wanting to binge PragDave’s course the past few days; the structure and simple explanations, Dave’s chill-ass vibe + straight-forward examples have been jiving with me. I’m also several chapters into the first couple of introductory Elixir books; my strategy with them the past few days has been to read corresponding chapters after watching videos and doing coursework.

I’ll plan to check back in over the next few days with updates and will keep an eye out for any comments/questions/feedback! It’s been a really long time since I’ve felt the pure joy of learning a new programming language, and I’m so happy to be doing this right now. :grin:

p.s. an early highlight in my Elixir journey was @josevalim merging my PR to Elixir main this morning. I guess this means I’m officially an Elixir contributor! :tada: It might’ve been the most basic PR in the history of Elixir, but it feels good to contribute, and I hope it’s the first of many in this wonderful community :heart:

9 Likes
2

Before I forget, one of the early things I’ve spent some time wrapping my head around is pattern matching. In a future installment, I plan to share what helped me look at pattern matching from an FP/Elixir perspective instead of an OOP or assignment-focused perspective.

Urban Müller’s programming language is an adjective I might associate with this process :winking_face_with_tongue:

1 Like
3

Loving the dedication Charles! Reminds me of when I learnt Ruby :024:

This also reminds me of something!

When I was reading @pragdave’s book Programming Elixir (Pragprog) I tweeted saying I was reading his book and that it was stretching the ol grey matter “..and I like it!”. Anyway I thought it was a dumb tweet and thought Dave probably get’s enough people @mentioning him so I pretty much immediately deleted it. Next thing I know Dave has taken a screengrab of it and tweeted it! :lol:

I’m pretty sure that was when I got to pattern matching, so it will definitely feel a little mind bending! Just persevere and I’m sure you’ll be fine :023:

1 Like
4

It’s different, that’s for sure! I’m feeling more comfortable with it today, and I think a couple of keys came from one of Dave’s course sections. In it, he specifies a couple of key things:

  1. The left-hand side (LHS) is the pattern, not just a variable
  2. For a pattern to match, the shape of the two sides must be the same, and literal values in the pattern have to match the corresponding values in the right-hand side (RHS).

Using a list’s head and tail in the LHS of a pattern can sometimes look weird when it appears there are more things in the RHS, but the more patterns I see and play around with, the more natural it’s starting to feel. You’re 100% right about persevering – it just takes some time and patience!

Completely separately, I just vibe coded a Phoenix app to help me master all of the Enum module functions. Here’s a quick screenshot that I think is pretty straightforward:

enum
enum1200×741 40.7 KB

My goal with this is to get random exposure to different Enum functions and get hands-on experience writing them. My process is to read the documentation, search GitHub for some real-world implementations, and then go back and write and run the code.

Eventually, I’d like to add all of the different Elixir modules and their corresponding functions, but at this point in my learning journey it appears (at least according to Dave) that Enum is pretty essential for progressing further.

The code for this is in a local git repo, but I’ll try to make some time to push it upstream later today. I want to play around with some more functions, close/reopen my browser, and make sure things like persistence work before pushing it upstream. (Edit: I just noticed the “functions learned” tracker did not update after completing Enum.min_max/2, so this is an example of something i’d want to fix first. The docs formatting in the left panel is also very ugly.)

I’m also happy to share it as an open source project, but to anyone who reads this and checks out the repo when it’s available, please keep in mind that I’m not focused on Phoenix development quite yet, so I have not even looked at the code.

Once I start learning Phoenix I would be delighted for people to roast my code :fire: but since it’s not my focus right now I just don’t think I’d get much benefit from it. Happy to have my mind changed though!

2 Likes
5

Dude! I started learning Ruby (before Rails, for the same reasons) at around the exact same time you published this article. At the time, I read every single one of those books (including the ones you mention at the end – lots of love for the Pickaxe book :heart: ), and I wish I could remember if I read your post! (Feels like I must have.)

I really appreciate your foundational approach to learning frameworks because it resonates with the way I was trained and how I like learn in general. As you recognized, I’m taking a similar approach with Elixir/OTP. While I’m eager to start building with Phoenix (and maybe Ash), I believe the more I learn about the foundational stuff (including the BEAM), the more fun I’ll have building cool stuff soon afterwards.

Thank you for sharing your blog post – it was very well written and a nice trip down Memory Lane! :grin:

1 Like
6

Here’s the repo for the Elixir Tutor Enum tool. It’s mostly functional and was super fun to put together over the course of my lunch hour today. I’ve had a good time learning about new-to-me Enum functions and writing code.

:police_car_light::police_car_light::police_car_light: If anyone wants to play around with this, please see the top of the README.md first. :police_car_light::police_car_light::police_car_light:

I can’t make any guarantees as to the fitness of this vibe-coded app. It’s probably pretty terrible for most people. :sweat_smile: For example, if you make any progress and then close your browser, you will lose all progress. I plan to fix this soon-ish for myself by adding some auth, but I don’t want to make any promises about when. So please be careful until then. Or fork it and do your own thing with it!

Another thing: I don’t want to derail my learning journal by focusing too much on vibe coding because my focus here is really all about mastering the fundamentals. This was just a fun lunch hour project that is helping expose me to some basic Elixir functionality. :slight_smile:

1 Like
7

PragDave’s course - that’s a great choice, I finished it a few years ago, it’s really good.

And pattern matching is absolutely incredible.

I do miss some language features from Haskell (e.g. partial application) but I’m having a ton of fun with Elixir as well!

3 Likes
8

I’m not familiar with Haskell, but I frequently see/hear mentions of it in the Nix community. I’ll have to check out partial applications!

In the past week I’ve finished “Learn Functional Programming with Elixir” to get me back in the FP mindset, “Programming Elixir ≥ 1.6” to prep me to finish Dave’s online course (I enjoyed being able to read the book with his voice in mind :), and I’m currently about 1/3 of the way through “Elixir in Action, Third Edition”.

Both of the former books were great reads, but so far my favorite is Saša Jurić’s “Elixir in Action”. Saša’s writing style and the way he presents the information in this book really resonates with me for whatever reason. Since I’m so new to the ecosystem I hesitate to make any opinionated recommendations to other newcomers about what’s good, but damn, this book has been outstanding so far.

I just got the Anki app for iOS so I could start using spaced repetition to reinforce some of the stuff I’m learning. I’m going to try using LLMs to extract my notes and highlights from book PDFs and epubs to seed the database. I saw another forum member’s 1,600-card database but that’s probably a little much for me right now when I’m more focused on just learning about the Enum module… Would be grateful for any ideas about Anki decks for Elixir/OTP newbies.

I splurged a little and got the Black Friday deal for Hugo’s and Alex’s “Elixir Patterns” book and Livebooks and am really excited about starting these, but first I want to finish Saša’s book, as well as Dave’s course and the PragProg course.

It feels like I’ve made a ton of progress over the past week, but every single day I realize I have so much more to learn (e.g. I’m getting really curious about Erlang now and have started to look into Joe Armstrong’s “Programming Erlang” and “Designing for Scalability with Erlang/OTP” by Francesco Cesarini and Steve Vinoski). I don’t think I’m going to accomplish my stretch goal of finishing both courses before the end of this week, but I should be finished with the introductory Elixir books I wanted to read in a couple of days. Next up are “Testing Elixir”, “Property-Based Testing with PropEr, Erlang, and Elixir”, and “Programming Ecto”. Once I’m finished with these I want to dive into the Phoenix framework so I can start building web apps.

I’m really looking forward to starting to build with these tools. As the foundational concepts of Elixir/OTP start to click I see so much potential for building really cool stuff.

1 Like
9

Wow, that’s great progress!

I also took the bait and bought two Elixir books from PragProg… Couldn’t resist 50% off… I got Building Table Views with Phoenix LiveView and Real-World Event Sourcing.

I’ve never tried flash cards for learning programming… Let me know how it works out!

Michal

2 Likes
10

@blazejcm , here’s my rough plan with the flash cards – create cards for:

  • the core concepts for each chapter (and maybe some more advanced topics)
  • key terms and definitions from each chapter
  • module functions, like Enum

Completely separately, I’m pretty pumped with my progress so far. As a little side note, I’m the type of person who likes to have a solid overall understanding of how the pieces of something fit together before diving in to start learning. Some people are comfortable just picking something up and learning bit by bit, but that’s never been a satisfying way to learn for me.

So I’ve recently finished “Elixir in Action”, “Programming Ecto”, “Programming Phoenix 1.4”, “Phoenix in Action”, and the brand new (and as yet, unfinished), “Ash Framework”, by @kamaroly . (Aside: I want to start using Ash in January; very coincidentally, I picked up Eric Evan’s DDD book several months ago and was delighted to see so some overlap with DDD principles in Phoenix and Ash. I see so much potential to apply these principles in this ecosystem.)

I didn’t complete every exercise in all of these books because my goal was to get a sense of what’s important to pay attention to before rolling up my sleeves with coding exercises from the video courses, as well as to make some mental and physical notes about where I can find more info as I start building.

I just fired up PragDave’s course before posting here – I realized it’s been a while since I shared here so I just wanted to pop by and say “hi”.

Does learning a new programming language remind anyone of that feeling they used to get when they were gifted a new video game or console as a kid? It’s like I’m starting out on a brand new adventure that I know is going to be challenging, but also very fun and rewarding.

4 Likes
11

Used to, but not anymore. Elixir was the last such experience in my life… and that was nine years and eight months ago.

IMO the whole novelty of new PLs peaks quite quickly. Or at least I got disillusioned by all the language wars.

It all depends on your goal however. If I were programming just for fun, my view would likely be much more excited and positive – like yours.

2 Likes
12

That’s a fair take, @dimitarvp . The last time I felt this way was more than a decade ago when I became a Rubyist. I appreciated how it was optimized for programmer happiness. I see that in the Elixir ecosystem now

On a personal note, my goal is to build stuff and be able to provide for my family, and I want the option to be able to do that as a solo dev or on a small team. Elixir/OTP + Phoenix (and maybe Ash) feels like a great potential fit for that.

1 Like
13

As I’m going through PragDave’s course I’m curious about his opinions regarding project structure vis-à-vis community standards or what’s considered idiomatic Elixir.

For example, in the “Let’s start coding > Start coding” section, there’s this bit:

Project Structure

I personally put the logic part of my code into a directory called lib/impl; most in the community instead use lib/hangman (or whatever your application is called) for all their application’s files.

You’ll start to see the benefits of having split directories when we look at processes.

I guess I’ll just have to wait and see about the benefits of having split directories, but I’m also curious about the pros and cons versus what “most in the community instead use”.

14

For all my 24 years of career, I never once found a good dir + file structure I was happy with. Nothing quite clicked. I think the problem is that many relationships between entities are forming a graph whereas the filesystems are trees.

But I did find a lot of super convinced advocates of a number of strange conventions i.e. order/read.ex and order/delete.ex… one action per file! Madness. Though I’ll admit it makes it a touch easier for fuzzy searching a filename or file contents. This approach gets a few points more in marks.

IMO the Unison language is the only one who gets this right; content-addressed code. In the meantime, before all PLs finally reailze its the 21st century, projects could become f.ex. a singular SQLite database indexed by a number of fields i.e. domain, namespace, implemened behaviours / protocols, app code vs. test code, and such. Also add arbitrary tags and propose a few hundred standard ones.

The whole thing of dir → file(s) → module(s) → function(s) is hugely outdated and has been for at least 20 years.

But again, I am not super against entity/action.ex. It makes fuzzy searching a little easier. Though I never had problems when doing fuzzy search for f.ex. def list_ (assuming using normal Phoenix generators) and finding what I need in literal two seconds.

1 Like
15

Hey,

Like you, I too am new to Elixir and am learning. I will preface by saying that I think we learn (or chose to learn) quite differently, so this recommendation may or may not be great for you. It appears to me that you are methodically creating a learning plan and working through it (which is awesome). I, on the other hand, prefer to just jump in and try stuff. One of the first things I did was to build a GenServer (barely understood what I was doing) that kept a tree data structure in memory. In my case, that was a quick sanity check, go/no-go choice on whether to adopt Elixir.

That disclaimer said, I found a series on YouTube of Jose doing the advent of code in 2021 to be very useful for me: https://www.youtube.com/playlist?list=PLNP8vc86_-SOV1ZEvX_q9BLYWL586zWnF. It felt a bit like the good bits of pair programming, wherein I got to experience writing Elixir as if I ‘knew what I was doing’.

For me it helped to see the language being written wholistically, rather than as a series of concepts. For example, rather than learning about cond as part of branching functions and then later learning about pattern matching, they might be demonstrated working together to solve a particular problem.

Anyway, check it out, maybe it will help =).

2 Likes
16

Welcome to the community. Personally, I would recommend starting with one Elixir book, then one Phoenix book, and then trying to build something immediately after that. Phoenix book in particular will most likely cover testing as well as Ecto, to a reasonable depth. From there, you can use the books to supplement your knowledge.

Don’t get me wrong, I love reading books. But at your level of experience, I think you’d gain a lot more from doing.

Ash has been growing in popularity, but it’s also both not necessary for building things, and is very different than basically everything else in the ecosystem. Good to read if you want to improve your employability. OK to skip for now otherwise.

2 Likes
17

Thank you for sharing José’s AOC videos – I look forward to checking these out!

I’d hazard a guess that Prag Dave’s course is similar in the sense that it felt a lot like pair programming. It’s probably the least expensive of all the courses I’ve signed up for and I’d also recommend checking it out.

18

Thanks for the feedback!

When I tackle something new I like to get a comprehensive overview first, and then dig in as necessary. It might be unconventional, but I’ve found that I tend to move faster when I have a good understanding of how all of the pieces fit together. It’s also just a lot more of a satisfying feeling for me :slight_smile:

As for Ash, I have a hunch it’s going to help me build things very quickly. I probably mentioned this somewhere here before, but months before learning about Ash I read Eric Evan’s Domain-Driven Design book, so I kind of feel like stumbling into the Elixir ecosystem, and then “discovering” the Ash Framework, was kismet.

I also really appreciate the declarative nature of the framework; this is one of the many reasons I’ve been going all in with Nix/NixOS.

As for my overall learning journey, I’ve been pretty heads down for the past few weeks. I’m currently about 1/3 of the way through the Pragmatic Studio’s Full-Stack Phoenix course, and have finished their Elixir & OTP course, as well as Prag Dave’s course. I picked up some other resources during Black Friday sales, but I’ll share more about those later. :slight_smile:

Before joining the Elixir ecosystem I had a very specific idea of what I wanted to build, but I wasn’t clear on how to build it. I’m still not entirely clear on how to build it, but I’m getting closer every day.

However, before then, I think the next logical step is to build a bunch of little things as quickly as I can. There are just a few more things I want to check off my learning list before I start…