Joseph Koski
@jkwa.bsky.social
đ€ 283
đ„ 796
đ 29
Author of Functional Programming with Elixir (beta, PragProg). Writing at joekoski.com.
New post in my Ash Framework series. This time Iâm lifting a few of Ashâs DSL ideas (or stealing them outright) to build an Either DSL in Funx.
www.joekoski.com/blog/2025/12...
#elixirlang
@pragprog.com
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Ash Framework: Lessons from its DSL
Lifting (or perhaps stealing) some of Ashâs good ideas.
https://www.joekoski.com/blog/2025/12/01/ash_dsl_1.html
3 days ago
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A new post in my series on the Ash Framework. This one looks at calculations and includes functional programming strategies for managing uncertainty.
www.joekoski.com/blog/2025/11...
#elixirlang
@pragprog.com
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Ash Framework: Calculations and Uncertainty
How Ash calculations work and ways to deal with missing or uncertain data.
https://www.joekoski.com/blog/2025/11/24/ash-calc.html
10 days ago
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reposted by
Joseph Koski
The Pragmatic Bookshelf â
15 days ago
When the work of our authors intersects, it's amazing. Such a privilege to provide a platform for all these talented, passionate humans. And, their books are included in our Black Friday, 50% off sale!
add a skeleton here at some point
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A new post in my series on the Ash Framework. This one explores the underlying mechanics of Ash validation and where Funx can help when checks need more structure or concurrency.
www.joekoski.com/blog/2025/11...
#elixirlang
@pragprog.com
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Ash Framework: Diving into Validation
âThatâs just, like, your opinion, man.â âThe Big Lebowski (1998)
https://www.joekoski.com/blog/2025/11/16/ash-validation.html
17 days ago
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Another in my series on the Ash Framework. Understanding actions from a functional programming perspective.
www.joekoski.com/blog/2025/11...
#elixirlang
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Ash Framework: A Closer Look at Actions
Time for a closer look at actions.
https://www.joekoski.com/blog/2025/11/09/ash-after_action.html
23 days ago
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Yet another in my series on the Ash Framework. I wanted to explore what itâs like to bring Ash into an existing project.
www.joekoski.com/blog/2025/11...
#elixirlang
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Ash Framework: Evaluating Ash for Existing Systems
How difficult is it to incorporate Ash into an existing codebase?
https://www.joekoski.com/blog/2025/11/02/ash-existing-systems.html
about 1 month ago
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Adding to my series on the Ash Framework book. Exploring how Ash works with Ecto and taking the opportunity to try a promising new library called Electric.
www.joekoski.com/blog/2025/10...
#elixirlang
@pragprog.com
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Ash Framework: Combining Ash Writes with Electric Reads
Exploring how Ash implements Ecto.
https://www.joekoski.com/blog/2025/10/27/ash-electric-1.html
about 1 month ago
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reposted by
Joseph Koski
The Pragmatic Bookshelf â
about 2 months ago
Beta Update Advanced Functional Programming with Elixir by @jkwa.bsky.social Model Behavior, Manage Complexity, and Maximize Maintainability
pragprog.com/titles/...
B5.0 Release Notes: * Production complete. On to layout & print. (Already purchased? Check your email for a download link.)
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Adding to my series on the Ash Framework book. Taking a closer look at messy authorization.
www.joekoski.com/blog/2025/10...
#elixirlang
@pragprog.com
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Ash Framework: Why Authorization gets Messy
Where is the mess?
https://www.joekoski.com/blog/2025/10/20/ash-authorization-2.html
about 1 month ago
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Back from vacation and I thought I'd add to my series on the Ash Framework book. Why does authorization logic get messy?
www.joekoski.com/blog/2025/10...
#elixirlang
@pragprog.com
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Ash Framework: Authorization and Monoids
Authorization logic gets messy fast.
https://www.joekoski.com/blog/2025/10/13/ash-authorization-1.html
about 2 months ago
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reposted by
Joseph Koski
The Pragmatic Bookshelf â
about 2 months ago
Alongside the book, youâll find a production-ready library that implements these abstractionsâfully tested, well documented, and ready to use. Advanced Functional Programming in Elixir by @jkwa.bsky.social
pragprog.com/titles/...
40% off through the weekend with code Pragpicks
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Next in my series on the Ash Framework book. What makes Ash different?
www.joekoski.com/blog/2025/10...
#elixirlang
@pragprog.com
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Ash Framework: The Coordination Problem
Not organization but coordination.
https://www.joekoski.com/blog/2025/10/06/ash-coordination.html
about 2 months ago
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I learn best by writing, so I wrote up some higher-level notes on Ash from the Ash Framework book. I thought others might find it useful:
www.joekoski.com/blog/2025/10...
#elixirlang
@pragprog.com
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Ash Framework: My Misconceptions
Itâs all about the domain.
https://www.joekoski.com/blog/2025/10/02/ash-misconception.html
2 months ago
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I walked away from ElixirConf thinking it was time to take a serious look at Ash. I donât have time to wander around, so I picked up the Ash Framework book. Halfway through, I get it.
pragprog.com/titles/ldash...
#elixirlang
@pragprog.com
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Ash Framework
Explore the power of Ash Framework by modeling and building the domain for a real-world web application.
https://pragprog.com/titles/ldash/ash-framework/
2 months ago
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An early reader had a suggestion. Connect functional programming patterns to the libraries Elixir devs already use. Itâs a good idea, but I didnât have space in the book.
www.joekoski.com/blog/2025/09...
#elixirlang
#funx
#PragProg
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Whatâs an Effect?
How do we handle side effects in a pure functional system?
https://www.joekoski.com/blog/2025/09/24/effect-monad.html
2 months ago
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reposted by
Joseph Koski
Jonatan MĂ€nnchen
2 months ago
One package. One update. A worm crawling through the BEAM ecosystem. A dark âwhat ifâ â and how we can stop it before itâs real.
erlef.org/blog/securit...
#erlang
#elixirlang
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Advanced Functional Programming with Elixir just climbed back to #1 on the @PragProg best seller list!
pragprog.com/best_sellers/
#afpelixir
#elixirlang
2 months ago
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Want to tinker? Sharing to see what folks think.
www.joekoski.com/blog/2025/09...
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Can an LLM Tutor?
âIâm not even sure whatâs real anymore.â âThe Matrix (1999)
https://www.joekoski.com/blog/2025/09/18/tutor.html
3 months ago
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PragProg is running a 48-hour flash sale â 45% off all books with code flashsale That includes my book Advanced Functional Programming with Elixir Sale runs Sept 18â20, 9am CT Grab it here:
pragprog.com
#pragprog
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Pragmatic Bookshelf: By Developers, For Developers
We improve the lives of professional developers. We create timely, practical books on classic and cutting-edge topics to help you learn and practice your craft, and accelerate your career. Come learn ...
https://pragprog.com
3 months ago
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reposted by
Joseph Koski
Elixir Radar
3 months ago
Elixir Radar issue 484is out! đŁ You can read it here:
buff.ly/vWcu6fa
This issue comes with content from
@peerstr.bsky.social
@jkwa.bsky.social
@mikezornek.com
@josevalim.bsky.social
, Mike Hostetler and Sven Van Caekenberghe .Thank you!
#ElixirLang
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Elixir Radar 484
https://buff.ly/vWcu6fa
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Another deleted scene from my book: There are many ways to solve equality: duck typing, injection, protocol dispatch. Here's why Funx uses the one it does:
www.joekoski.com/blog/2025/09...
#elixirlang
#funx
#AFPElixir
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Polymorphism and Behavior Injection
When are two things the same?
https://www.joekoski.com/blog/2025/09/16/ad-hoc-polymorphism.html
3 months ago
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reposted by
Joseph Koski
Nicholas Henry
3 months ago
I đ this passage from
@jkwa.bsky.social
buff.ly/xIVq6gW
"... understanding doesnât parallelize, and complexity doesnât distribute. Each new contributor must climb the same tangled mess... even more time is spent coordinating, clarifying, and patching over mismatches in mental models."
#elixirlang
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Advanced Functional Programming with Elixir
Use advanced functional programming principles, practical domain-driven design techniques, and production-ready Elixir code to build scalable, complex systems from simple, reusable components.
https://pragprog.com/titles/jkelixir/advanced-functional-programming-with-elixir/
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Funx now has Livebooks. I considered a plugin, but thought this might be a good job for an LLM. This short post covers my strategy:
www.joekoski.com/blog/2025/09...
#elixirlang
#funx
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Generate Livebooks with an LLM
So many loopsâŠ
https://www.joekoski.com/blog/2025/09/14/transcribing-livebooks.html
3 months ago
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Most personal blogs are in the low hundreds of unique visitors per month. Mine was too. This month I passed a milestone.
#elixirlang
3 months ago
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I just finished putting together interactive Livebook notebooks for every chapter of Advanced Functional Programming with Elixir. You can now run all the examples in your browser. Or like me, spin them up locally with Docker:
www.joekoski.com/blog/2025/09...
#elixirlang
hashtag#AFPElixir
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Livebook Examples from Advanced Functional Programming with Elixir
It feels a bit impolite to ask readers to download code and type mix commands just to run the examples. We have better tools now.
https://www.joekoski.com/blog/2025/09/10/livebooks.html
3 months ago
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Just checked in to see if Funx had hit 80 downloads. Any ideas on what happened?
www.joekoski.com/blog/2025/09...
#elixirlang
#funx
#AFPElixir
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What is going on?
âThey found me. I donât know how, but they found me.â â Dr. Emmett Brown
https://www.joekoski.com/blog/2025/09/10/hex-spike.html
3 months ago
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Some comments on an earlier post had me thinking about polymorphic equality in Elixir, and how == can fall short.
www.joekoski.com/blog/2025/08...
#elixirlang
#AFPElixir
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Whatâs the point of a polymorphic eq?
Why not keep equality inside the module where it belongs?
https://www.joekoski.com/blog/2025/08/26/polymorphic_eq.html
3 months ago
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Just got The BEAM Book by Erik Stenman in the mail. Time to go spelunking in the BEAM!
#elixirlang
#erlang
#beam
#AFPElixir
3 months ago
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Follow-up post on polymorphism in Elixir. This one looks at how structs help avoid pitfalls from other languages.
www.joekoski.com/blog/2025/08...
#elixirlang
#AFPElixir
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Polymorphism and Structs in Elixir
Polymorphism has always relied on tags. Elixirâs structs make them safer.
https://www.joekoski.com/blog/2025/08/23/elixir-structs.html
3 months ago
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I wrote this post about polymorphism in Elixir. Details I wish I had known five years ago.
www.joekoski.com/blog/2025/08...
#elixirlang
#AFPElixir
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Polymorphism in Elixir
This post walks through the basics of protocols in Elixir. Itâs the information I wish I knew five years ago.
https://www.joekoski.com/blog/2025/08/20/elixir-polymorphism.html
3 months ago
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Why is learning FP so hard? I wrote a short post on my blog about this a couple of weeks back.
www.joekoski.com/blog/2025/08...
#Elixir
#LearnFP
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Why Is This So Hard?
A blog about software development, data science, and other things I find interesting.
https://www.joekoski.com/blog/2025/08/20/book-reason.html
3 months ago
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reposted by
Joseph Koski
{:ok, Noah}
3 months ago
I can already tell I'm going to be spending most of my labor day reading through the beta edition of
@jkwa.bsky.social
's
@pragprog.com
book:
pragprog.com/titles/jkeli...
#ElixirLang
#FunctionalProgramming
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Advanced Functional Programming with Elixir
Use advanced functional programming principles, practical domain-driven design techniques, and production-ready Elixir code to build scalable, complex systems from simple, reusable components.
https://pragprog.com/titles/jkelixir/advanced-functional-programming-with-elixir/
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reposted by
Joseph Koski
Margaret Eldridge
4 months ago
Celebrating Advanced Functional Programming with Elixir by Joseph Koski now in beta! đ Read more:
bit.ly/3V5AQBZ
đ ebook:
pragprog.com/titles/...
#Elixir
#functionalprogramming
#MyElixirStatus
#WeBEAMTogether
#programming
#pragprog
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