Elixir Wizards

Zack Kayser, Staff Software Engineer at cars.com, joins Elixir Wizards Sundi Myint and Charles Suggs to discuss how Cars.com adopted a server-driven UI (SDUI) architecture powered by Elixir and GraphQL to deliver consistent, updatable interfaces across web, iOS, and Android.

We explore why SDUI matters for feature velocity, how a mature design system and schema planning make it feasible, and what it takes, culturally and technically, to move UI logic from client code into a unified backend.

https://cars.com

Special Guest: Zack Kayser.

Rustler Core Team Member Sonny Scroggin joins Elixir Wizards Sundi Myint and Charles Suggs. Rustler serves as a bridge to write Native Implemented Functions (NIFs) in Rust that can be called from Elixir code. This combo leverages Rust's performance and memory safety while maintaining Elixir's fault tolerance and concurrency model, creating a powerful solution for CPU-intensive operations within Elixir applications.

Sonny provides guidance on when developers should consider using NIFs versus other approaches like ports or external services and highlights the considerations needed when stepping outside Elixir's standard execution model into native code.

Looking toward the future, Sonny discusses exciting developments for Rustler, including an improved asynchronous NIF interface, API modernization efforts, and better tooling. While Rust offers tremendous performance benefits for specific use cases, Sonny emphasizes that Elixir's dynamic nature and the BEAM's capabilities for distributed systems remain unmatched for many applications. Rustler simply provides another powerful tool that expands what developers can accomplish within the Elixir ecosystem.

https://github.com/rusterlium/rustler

Getting Started:

Special Guest: Sonny Scroggin.

Today on Elixir Wizards, hosts Sundi Myint and Charles Suggs catch up with Sean Moriarity, co-creator of the Nx project and author of Machine Learning in Elixir. Sean reflects on his transition from the military to a civilian job building large language models (LLMs) for software. He explains how the Elixir ML landscape has evolved since the rise of ChatGPT, shifting from building native model implementations toward orchestrating best-in-class tools.

We discuss the pragmatics of adding ML to Elixir apps: when to start with out-of-the-box LLMs vs. rolling your own, how to hook into Python-based libraries, and how to tap Elixir’s distributed computing for scalable workloads. Sean closes with advice for developers embarking on Elixir ML projects, from picking motivating use cases to experimenting with domain-specific languages for AI-driven workflows.

https://hexdocs.pm/nx/intro-to-nx.html

Special Guest: Sean Moriarity.

Mark Ericksen, creator of the Elixir LangChain framework, joins the Elixir Wizards to talk about LLM integration in Elixir apps. He explains how LangChain abstracts away the quirks of different AI providers (OpenAI, Anthropic’s Claude, Google’s Gemini) so you can work with any LLM in one more consistent API. We dig into core features like conversation chaining, tool execution, automatic retries, and production-grade fallback strategies.

Mark shares his experiences maintaining LangChain in a fast-moving AI world: how it shields developers from API drift, manages token budgets, and handles rate limits and outages. He also reveals testing tactics for non-deterministic AI outputs, configuration tips for custom authentication, and the highlights of the new v0.4 release, including “content parts” support for thinking-style models.

Key topics discussed in this episode:

• Abstracting LLM APIs behind a unified Elixir interface

Links mentioned:

Getting started:

Special Guest: Mark Ericksen.

Connor Rigby joins the Elixir Wizards to talk about Blue Heron BLE (Bluetooth Low Energy) support for Elixir apps. Blue Heron implements the BLE specs in pure Elixir, leveraging binary pattern matching and concurrent message processing to handle Bluetooth protocols. Unlike most solutions that require C ports or NIFs, Blue Heron runs entirely in user space, so it works seamlessly in both Nerves-based embedded projects and (eventually) desktop Elixir applications.

We discuss how Nerves development differs from building Phoenix apps. Connor shares challenges he's experienced with hardware compatibility, where some chips only partially implement the spec, and he discusses the surprisingly deep (but sometimes incomplete) world of BLE device profiles. His tip for anyone entering the BLE space: read the official spec instead of trusting secondhand blog posts. Tools like Nerves LiveBook give you hands-on examples, so you can get a BLE prototype running on a Raspberry Pi and your phone in no time.

https://github.com/ConnorRigby/

Special Guest: Connor Rigby.

In the Season 14 premiere, hosts Dan Ivovich and Sundi Myint chat with Isaac Yonemoto, creator of the Zigler library, to explore how Zigler brings Zig’s performance and safety to Elixir through Native Implemented Functions (NIFs). Isaac walks through the core design of Zigler and how it auto-generates the Elixir-to-Zig bridge, enforces type safety, and exposes multiple execution modes (normal, dirty, threaded). The conversation covers real-world applications, from SIMD-powered token selection for LLM hardware acceleration to OTP-style fault tolerance in low-level code.

Isaac shares his own journey: stepping back from professional software work to launch a biotech startup focused on reducing drug manufacturing costs while continuing to maintain Zigler and even leveraging Elixir for bioinformatics pipelines.

https://github.com/E-xyza/zigler

For the Season 13 finale, Elixir Wizards Dan and Charles are joined by Spin42 Engineers Marc Lainez, Thibault Poncelet, and Loïc Vigneron to discuss their work retrofitting a 2007 VW Polo and creating an Open Vehicle Control System (OVCS). Using Elixir, Nerves, and Raspberry Pis, the team is reimagining vehicle technology to extend the lifespan of older cars and reduce waste—all while making the process approachable and open source.

The Spin42 team shares the technical details behind OVCS and how they use Elixir and Nerves to interact with the CAN bus and build a Vehicle Management System (VMS) to coordinate various vehicle components. They dive into the challenges of reverse engineering CAN messages, designing a distributed architecture with Elixir processes, and ensuring safety with fail-safe modes and emergency shutoffs.

Beyond the technical, the team discusses their motivation for the project—upgrading older vehicles with modern features to keep them on the road, building an open-source platform to share their findings with others, and above all-- to just have fun. They explore potential applications for OVCS in boats, construction equipment, and other vehicles, while reflecting on the hurdles of certifying the system for road use.

If you’ve ever wondered how Elixir and Nerves can drive innovation beyond software, this episode is packed with insights into automotive computing, hardware development, and the collaborative potential of open-source projects.

https://www.spin42.com/

Special Guests: Loïc Vigneron, Marc Lainez, and Thibault Poncelet.

The Elixir Wizards welcome Jim Freeze, organizer of ElixirConf and creator of the Horizon library. Jim shares his journey from organizing Ruby conferences to founding and growing ElixirConf into the community cornerstone it is today. He reflects on the challenges of running a major conference, how COVID-19 shaped the event, and why the talks remain an evergreen resource for the Elixir ecosystem.

We discuss Horizon, Jim’s deployment library for Elixir and Phoenix applications with Postgres on FreeBSD. Driven by a need for simplicity and cost-effectiveness, Jim explains how Horizon minimizes external dependencies while delivering fault-tolerant and streamlined setups. He compares it to tools like Fly, Terraform, and Ansible, highlighting its low cognitive load and flexibility—key benefits for developers seeking more control over their deployment environments.

Jim also unpacks the broader value of understanding and customizing your deployment stack rather than relying solely on managed services. He discusses the benefits of using FreeBSD, including its stability, security, and performance advantages, as well as its robust ZFS file system.

Jim emphasizes the importance of coherent deployment workflows, community collaboration, and contributions to open-source projects like Horizon. He invites listeners to explore Horizon, share feedback, and own their deployments.

Nine Minutes of Elixir

Special Guest: Jim Freeze.

Zack Kayser and Ethan Gunderson, Software Engineers at Cars Commerce, join the Elixir Wizards to share their expertise on telemetry and observability in large-scale systems. Drawing from their experience at Cars.com—a platform handling high traffic and concurrent users—they discuss the technical and organizational challenges of scaling applications, managing microservices, and implementing effective observability practices.

The conversation highlights the pivotal role observability plays in diagnosing incidents, anticipating system behavior, and asking unplanned questions of a system. Zack and Ethan explore tracing, spans, and the unique challenges introduced by LiveView deployments and WebSocket connections.

They also discuss the benefits of OpenTelemetry as a vendor-agnostic instrumentation tool, the significance of Elixir’s telemetry library, and practical steps for developers starting their observability journey. Additionally, Zack and Ethan introduce their upcoming book, Instrumenting Elixir Applications, which will offer guidance on integrating telemetry and tracing into Elixir projects.

https://www.carscommerce.inc/

Special Guests: Ethan Gunderson and Zack Kayser.

AJ (Alykhan Jetha), CEO and CTO of Marketcircle, joins the Elixir Wizards to share his experience building and evolving Daylite, their award-winning CRM and business productivity app for Apple users. He details his experiences as a self-taught programmer and how Marketcircle has navigated pivots, challenges, and opportunities since its founding in 1999.

AJ explains why they migrated Daylite’s backend to Elixir, focusing on their sync engine, which demands high concurrency and fault tolerance. He highlights how Elixir has improved performance, reduced cloud costs, and simplified development with its approachable syntax and productive workflows.

The conversation also touches on the technical hurdles of deploying native apps for Apple devices and the potential for integrating new technologies like LiveView Native to streamline cross-platform development.

For technical founders, AJ emphasizes the importance of leveraging your strengths (“superpowers”), staying deeply connected to the development process, and finding stability in tools like Elixir amidst a rapidly evolving tech ecosystem. He also shares Marketcircle’s roadmap for migrating more customers to Elixir-powered systems and explores the potential for new features in their native apps.

Tune in for insights on building resilient systems, navigating technical and business challenges, and how Elixir is shaping Marketcircle’s future.

https://www.marketcircle.com/

Special Guest: Alykhan Jetha.