The ElixirTalk Podcast

Taking questions from around the Elixir community about application design principles and the state of the ecosystem. Ask us a question!

Episode 165 feat. José Valim

Episode 165 - José Valim on Bytepack, Open Source, and LiveView changes in Phoenix 1.5

Chris and Desmond are backed by a very special guest; José Valim! You might know José as the creator of the Elixir programming language and we’re excited to have him back as a 3rd time guest on the show. José walks us through a brand new Dashbit project, Bytepack which is a way to package and sell software projects and takes all of the hassle out of the process today. We dig into Bytepack and discuss sustainable open source, Dashbit, and more.

As well as that we also hear about the new Phoenix 1.5 features, LiveDashboard, all of the great new LiveView enhancements, some nice new Elixir additions and much more! A lot of links in this episode, think we got them all below but let us know if we missed anything 👇


Episode 164 - Quarantine Special: Module Organization in Elixir

We’re back with another episode of ElixirTalk. In this episode Chris & Desmond do a deep dive on organizing code in Elixir and talk about some best practices. We recorded this a couple weeks ago so it may sound a little stale :)

We touch on:

  • Module and context naming
  • How we like to organize code in our projects
  • Big long modules vs many small modules
  • How to split up contexts
  • Injecting code via macros


Episode 163 - EMPEX LA Recap, Project Management Tools, and Monitoring

We’re back with a recap with another episode of ElixirTalk. In this episode we cover quite a few topics; an EMPEX LA recap, a foray into project management tools that we like and use (!), and then we round things out by talking about Chris integrating App Signal into his API at Muru.

It’s a fun, jam packed episode with us going all around through many topics and go longer than we thought and off on an ops tangent (as usual).

Times of topics:

  • Intro [00:00 - 03:40]
  • EMPEX LA Recap [03:40 - 17:10]
  • Project Management Tools: [17:10 - 25:40]
  • Monitoring / Metrics / Instrumentation: [25:40 - 39:30]
  • Close [39:30 - 41:00]


Episode 162 feat. Bruce Tate

Episode 162 - Designing Elixir Systems with Bruce Tate

It’s another episode of ElixirTalk, this time Chris and Desmond are joined by the one and only Bruce Tate author of many notable titles such as Programming Phoenix and Seven Languages in Seven Weeks, as well as being a frequent speaker on the circuit. We dig into the new Designing Elixir Systems with OTP book, that James Edward Gray, II and Bruce co-authored. We talk a lot about the way systems are put together, going into depth about the ‘Do Fun Things with Big, Loud Worker-Bees’ pattern that’s advocated for in the book. Along the way we talk about software design, persistence and more. Come along for the ride, it’s a fun one!


Episode 161 feat. Todd Resudek

Episode 161 - feat. Todd Resudek

We’re back with another episode of ElixirTalk, this time joined by the one and only Todd Resudek who gives us a run through of his talk at this years EMPEX LA entitled “It’s Time to Embrace Erlang”. Listen in to hear us discuss Todd’s nerve projects (including his recent LiveView Smart Mirror), why Todd thinks learning you some Erlang as an Elixir developer is important, and even about Hollywood Hogan and some other wrestling trivia. This show has it all.


Episode 160-A new decade, Plataformatec acquisition, Elixir 1.10-rc and more

We’re back! It’s been a while but it’s 2020 and Chris and Desmond are back with a new episode for the new decade. In this very timely episode we dive into the big community news; Plataformatec being acquired and what that means for the community and the new Elixir v1.10-rc.0 release. After that, we accidentally stray once again into a spirited discussion about ops, Kubernetes, and picking technology that suits you right now. Desmond provides some controversial opinions and we kick off the new year with a bang :boom:

Links in the show notes

Episode 159 - Property-Based Testing & Authorization in APIs

Chris and Desmond are back! In this episode we talk about Desmond’s exploration into Property-Based testing, and then do a deep dive into authorization and access control in Chris’ GraphQL API. Property-based testing is a new world for both of us, but we do our best to tell you all about what libraries to use and how we’re thinking of using it. Chris is deep in some reworking of the authorization code in his GraphQL API and we go into depth talking about how it is structured, some of the challenges of building a flexible authorization system and then how this integrates back into a system. After talking about authorization we then go into validation of parameters in our APIs and how we think about typing and validating them at the boundaries, and in our Ecto Schemas.


Episode 158 - Oban, Background Jobs, Concurrency, and Is Elixir Even Worth It?

Episode 158 - Oban, Background Jobs and Designing Resilient Systems in Elixir.

In this episode of ElixirTalk Chris & Desmond dive into background jobs using Oban, a new library that relies on Postgres to add persistence to job scheduling. We discuss why you’d want to reach for a library like Oban in the first place, which leads us to a discussion on distributed systems design, failure handling, and some of the gotchas of modeling everything in-memory. We’ve added some extra reading in the links belong for some articles that we didn’t mention in the episode, but might serve as good reading material regardless.


Episode 157 feat. Chris McCord - LiveView/Phoenix part Deux

Episode 157 – LiveView & The Future of Phoenix ft. Chris McCord

Today on ElixirTalk we’re joined by Chris McCord who you may know as the creator of the Phoenix framework, and a second time guest on ElixirTalk. In this episode we talk quite a bit about LiveView, the journey of taking it from a prototype to release, the optimizations that have come along the way, and some of the great examples of LiveView running today. We get into some of our previous discussions about the balance of LiveView vs Javascript with Chris and how we frame the benefits of using the technology today. Additionally we hear about what’s on the roadmap for Phoenix, and the roadmap outside of the Phoenix core library itself. Thanks as always to Chris and the Phoenix Core team for their work!


Episode 156 - Desmond's new Job, Managing Complexity, and Designing Systems

Episode 156 - Desmond & Chris face-to-face

In todays special episode Desmond and Chris are together in NYC in-person for the first time in the history of recording Elixir talk. In the episode we dig into Desmond’s new role as CTO at Payitoff and talk about how Elixir helps in managing the complexity of student loans processing. We also discuss best practices in Elixir, some common gotchas in working in the language and more.

Todays topics include:

  • Using tuples and tagged tuples
  • Structuring control flow for Elixir
  • Enforcing conventions in your codebase
  • Behaviours vs Protocols


Episode 155 feat Brian Cardarella, Luke Imhoff, Paul Schoenfelder, and Hans Elias Josephsen - Lumen!

Episode #155 - A special look into Lumen

Today we have an extra special episode for you where we dig into a project you may have seen announced at the recent US Elixir Conference; Lumen, which is an alternate BEAM implementation, designed for WebAssembly. On the show we’re joined by the core members of the Lumen team: Brian Cardarella, Paul Schoenfelder, Luke Imhoff, and Hans Elias Bukholm Josephsen. We get into a lot of the details about the project; why it exists, what the goals are, what the hell web assembly is, and where it’s going. Join us and get a glimpse of a future direction for Elixir!


Episode 154 - A Great Intro, ElixirConf Recap, Javascript v LiveView

ElixirTalk Episode 154 – ElixirConf recap and more!

We’re back with another ElixirTalk episode after a short break! This time featuring Chris and Desmond reflecting on a great ElixirConf! We discuss our standout talks, as well as digging into the keynotes from Dockyard (Lumen), José Valim, Justin Schneck and Chris McCord.

At the end of the episode we debate LiveView and it’s place in the broader JS ecosystem. Chris and Desmond somewhat disagree in this case. Let us know your thoughts, we’d love to hear more on this hotly debated subject.


Episode 153 feat. Dave Lucia- The Dream Stack with Rust & Elixir

Episode 153 – The Dream stack with Rust & Elixir feat. Dave Lucia

We kick things off by hearing about the newly launched Elixir Training :tada: which y’all should check out if you’re looking to learn the language, or have friends who might. In todays episode we’re joined by Dave Lucia, VP of Engineering at SimpleBet where we hear about the use of the “Dream Stack” (you heard it here first folks!), which is Elixir using Rust NIFs for performance reasons (in their case calculating real-time betting odds). We spend a lot of time in the episode digging into what NIFs are, why Rust is a good fit for writing Elixir NIFs and what the pitfalls are. We get real technical with dirty schedulers, resource arcs in Rust, and all of the reasons for why you should and probably should not use NIFs unless you really need it. Also in an Elixir Talk first Dave turns around and asks us a question at the end. And in maybe a podcast first we place an on-air bet on who can donate the most to the Erlang Ecosystem Foundation. Links

Episode 152 - Hire an Elixir Developer! and Chris's Ecto Adventures

Episode 152 - The joys of Ecto

This week it’s a Chris & Desmond episode! We kick things off by hearing all about Desmond’s latest project – Hire an Elixir Developer – a job board to help companies attract Elixir talent that’s launching soon. We dig into how Desmond has been writing his latest project, hear a bit about how he’s using LiveView and how he’s chasing boring technology to get this project done (Phoenix & Elixir). Chris has also been writing lots of code this week (and has kept Elixirin’) – he talks a bit about how Elixir has mostly just been getting out of his way. We then dig into one of our favorite subjects … Ecto! We describe the joy of named binds, how we split up Ecto queries, and think about composing queries. We then go onto talk about lateral joins and the limits of Ecto preloads.


Episode 151 feat. Dave Thomas and Brian Mitchell - The Future of Elixir

Episode 151 – Dave Thomas & Brian Mitchell

In this special episode of ElixirTalk we are joined by Dave Thomas and Brian Mitchell where we continue a discussion that we had at EMPEX NYC this year as a fishbowl style format. If you haven’t yet seen the talk, you can do so here: –– probably best if you watch before listening, but you can also listen to this as a standalone episode. This episode is long, but is packed with some great tidbits about Elixir and Erlang and we go into considerable depth about how applications work today as well as outlining a vision for the future.

Key moments in the episode

  • Dave lays out some of the key tenants of his argument about augmenting OTP to work better for a world that we’re in today
  • Brian describes what OTP is and gives his thoughts on Dave’s initial thesis, questioning some of the static nature that Dave argues about OTP
  • Dave lays out that what we’re doing in Elixir and Phoenix land is the OTP way (for better or for worse) and questions whether this is the best way to do things?
  • We talk at length about configuration and how things work today in Elixir / Erlang. Brian does a great job of explaining the different tenants of configuration in OTP that exist and we dig into what a dynamic model might look like.
  • We then talk about supervisors as they work in OTP and describe the concept of dynamic lifecycle management and a future vision of supervision that goes beyond just processes and extends into system observability.
  • We discuss challenging conceived wisdom and why that helps move communities forward, looking at the interesting case of how Elixir inherits decisions from the Erlang community and how we might revisit some of those assumptions.

Links for this show

Episode 150 feat. Juan Facorro - Clojerl!

Episode 150 - Clojerl with Juan Facorro

This week on the show we’re joined by Juan Facorro, an avid Erlang-er and creator of Clojerl, a Clojure port written in Erlang.

We give you an update about Elixir Training, and tell you a bit more about a potential bar / meetup we at EMPEX will be hosting during ElixirConf this year in Denver (if we can find a bar).

We then get Juan to give us a run through of Clojerl, diving into the project, his motivations for creating it and going in-depth to some of the challenges Juan had along the way. We understand why you’d even want Clojure on the BEAM in the first place and where the Erlang concurrency model is advantageous here.


Episode 149 - It's just Chris and Desmond. And Elixir Training!

This week we don’t have a guest, so it’s just Chris & Desmond. We kick things off discussing our opening music and how weird it is listening to yourself on a podcast.

Desmond tells us about his exploration into webflow and his love (hate) for CSS. We dig into bits in the language that still trip us up, even now with our experience in the language. We dig into some Ecto: query syntax that trips us up, materialized views, application logic vs database logic and lots of other database goodies.

Desmond tells us how Phoenix contexts trip him up and we go into some depth about how both of us structure contexts and code in our Phoenix applications.

We tell you about ElixirTraining, which is our new venture to help teach more engineers the beauty of Elixir, as well as engineering leaders about why Elixir is a great fit for your organization.

Oh, and sorry we said we’d answer some community questions and then never did.


Episode 148 feat. Maxim Fedorov - Erlang at Scale in WhatsApp

Elixir Talk 148 - Feat Maxim Federov

Desmond gives us an update on his truck and the work he’s been doing there. Chris tells us about how he’s been getting back into coding and how he’s been writing Absinthe and GraphQL.

We announce a special new announcement: the launch of Elixir Training, our new business where we’re going out and looking to train more folks on Elixir across the US.

We also have a special guest on the show this week: Maxim Federov a Software Engineer at WhatsApp. We dive into some of the joys of using Erlang at bonkers scale (~1.5 billion+ users), using 10k servers and attempt to ask some moderately interesting questions, that Maxim answers like a champ.

Interesting links:

Episode 145 feat Fred Hebert - Erlang in Infrastructure, Property-Based Testing, and more!

Episode 144 feat. Martin Sumner - Riak and Erlang at the NHS

Episode 142 feat. Sophie DeBenedetto - Elixir at the Flatiron School, Learning Functional Languages


Episode 140 feat. Chris McCord - Phoenix LiveView!

Episode 139 feat. Zach Smith - EMPEX LA, ErlEF, Macros, and Functors, oh my!

Episode 137 feat. Devon Estes - Benchee, Assertions, and Opera, who knew?

Episode 136 - Our Github Flows, New Years Code Goals, and Realtime Thoughts


Episode 135 feat. Chris Hildebrand - Migrating an Elixir App Off Kubernetes


Episode 132 - Hello! and Macros. Lots of macros.

Episode 131 - The Big Elixir preview and EMPEX LA

Episode 130 - Desmond's (lost) Mustache, Ecto3, Database Views & Windows

Episode 127 - Scaling Desmond's App, Kubernetes, Property-Based Testing, and more!

Episode 127 - Scaling Desmond’s App, Kubernetes, Property-Based Testing, and more! by Elixir Talk

Episode 126 - Distillery 2, ElixirConf, and Your Communities

Episode 123 - Ecto!

Ecto, Ecto, and more Ecto! We discuss the different ways we use this versatile tool for much more than just database queries.

SHOW NOTES •…-sagas-583d1cd2b149 • • • •

Episode 122 - Event-Driven Architecture, Microservices, and evolving Application Architecture

How does Chris use an Event Bus in his app? Is it cool or is it lame? Also, how does your app grow, and what are the design rules you use to respond to that?

SHOW NOTES no notes this time!

Episode 121 - Editors & Workflow, Module Design, Imports & Aliases, and Function Typing

What editors do we use when writing Elixir? What’s our testing workflow? We also discuss why and when we use imports and aliases in our modules, and the pros and cons of typing our function calls. And Desmond has a new job!

show notes

Episode 120 feat. Mat Trudel - Timers in the VM, SchedEx, and Factory Automation

We chat with EMPEX NYC 2018 speaker Mat Trudel to discuss his SchedEx library, timers in the Erlang VM, factory automation, and more!

show notes

Episode 118 feat. Paul @bitwalker Schoenfelder - Deployment, Configuration, and more!

Our chat with the famous Paul Schoenfelder aka bitwalker, creator of Distillery, Swarm, and more! We discuss deployment strategies, the integration of Distillery into Mix, how the configuration discussion affects advances in deployment, and more.

show notes

Episode 117 feat. Andrew Summers - Dialyzer and its new Pretty Printer

We sit with Andrew Summers, contributor to the Dialyxir project and author of its new Pretty Printer.


Episode 116 - Injecting GenServer state, the Freedom Formatter, and Behaviours

We discuss injecting state into a new GenServer, Pete Gamache’s Freedom Code Formatter, and a question about whether using a Behaviour is invoking the pains of OOP inheritance.


Episode 115 - Our EMPEX Recap and Open Source Initiatives!

Our EMPEX Recap! We discuss our favorite talks, an Open Source proposal, and Dave Thomas’ controversial opinions about higher-level abstractions in Elixir.


Episode 114 - Training up Teams on Elixir

What are strategies for onboarding a team in Elixir?

Episode 113 - Typespecs, Tests, Hot Code Upgrades, and EMPEX!

show notes Typespec correction: EMPEX:

Episode 112 - Caching and Process in Production, Elixir Segment Libraries, Ready Player One review!

Episode 110 - When to Use/Not Use GenServers or Umbrella Apps

Lots of developers coming to Elixir misuse GenServers and Umbrella applications, thinking that just because they have these tools, they should use them. But that’s not always so!

Have a listen for our perspective on when to reach for GenServers and when not to.

Episode 109 - Authorization/Authentication in Phoenix apps, Higher-Level App Patterns

Episode 108 - Multiple Elixir Versions, How Much Erlang Should You Know, & Thinking Functionally

EMPEX LA is this weekend! Get your ticket to meet ElixirTalk hosts Desmond and Chris!

Episode 106 - Chat with José Valim

We hang out with José Valim, creator of Elixir, and discuss new features in Elixir 1.6, tips to build better applications, and (of course) Star Trek.

Episode 105 - Drop-in Libraries & Supervisors

Episode 104 - Storing State in Elixir Apps

How should you think about storing state in your Elixir apps? Should you use a traditional external datastore? Or one of the built-in constructs: GenServers, ETS, DETS, or mnesia?

Episode 103 - Umbrella Apps

When should you use Umbrella Apps?

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