Mark Cotner is a DBA managing around a thousand databases by day and a telecom CTO by night — building hospitality cable networks for RV parks, nursing homes, and apartment complexes at 100% annual growth. In this episode, he walks through the infrastructure, the business, and the two-year project that just landed on Hex: Timeless, an embedded observability suite for Elixir built on Rust NIFs, hitting 3 million metric inserts per second with 14:1 compression.

We get into what a hospitality network actually looks like — branded cable hardware, DOCSIS provisioning, and mesh Wi-Fi across dispersed sites — and how Mark's team handles monitoring across thousands of cable modems using a full Elixir stack (DHCP, TFTP, NTP, and Ash). He also shares how a frustrating Ansible setup led him to build something he thought should exist: a lightweight, embeddable observability backend that drops into a Phoenix app in under five minutes via Igniter, with less than 5% CPU overhead.

The technical core of the conversation covers the Timeless architecture in depth — PCO compression for metrics, OpenZL for logs and traces, 15 rounds of iteration before landing on a single consolidated Rust NIF, and why the Elixir-to-Rust translation layer ended up being the real bottleneck. Mark also talks benchmarking against Victoria Metrics on a 192-core AWS ARM instance, the custom C web server (Rocket) he built to cut HTTP latency 30x below Bandit, and how supervision trees let him pack an entire DOCSIS provisioning stack into one Elixir app without worrying about cascading failures.

Whether you're curious about Elixir in telecom, Rust NIF development, time series database internals, or just want to hear what 30 years of observability experience looks like applied to the BEAM, this one is packed.

Resources Mentioned:
- Timeless on Hex: https://hex.pm/packages/timeless_phoenix

Connect with Mark:
- X/Twitter: https://x.com/awksedgreep

SUPPORT ELIXIR MENTOR
- Elixir Mentor: https://elixirmentor.com

Sponsored by BEAMOps — scalable Elixir deployments and infrastructure migrations, authors of Engineering Elixir Applications: https://beamops.co.uk
Elixir AI Collective Discord — your community for coding Elixir with AI: https://agentjido.xyz/discord

George Millo — creator of Learn Phoenix Live View and alumnus of the Gauntlet AI fellowship — joins me to talk through what really changes when you commit to LLM-driven development. George went through Gauntlet's intensive 10-week program built around LLM maximalism, came out the other side rethinking how he builds software, and has spent the past year working on an AI-first engineering team applying those lessons in production.

We spend a lot of time on the practical realities of agentic coding: verification debt (the gap that grows between your mental model and what the AI actually built), the importance of planning before prompting, why George works in small self-contained PRs, and how he uses Codex and Claude Code in parallel tabs without losing track of what's happening. We also get into the debate around vibe coding, spec-driven development, testing pitfalls, and why deep technical knowledge matters more now — not less — when AI is writing most of the code.

The conversation covers where Elixir fits in an AI-first world: the BEAM's process model as a natural fit for agent architectures, Phoenix shipping with an agent.md file, Tidewave's approach to closing the feedback loop, and why Elixir's tooling consistency puts it ahead of the JavaScript fragmentation George deals with at his day job. We also get into the security risks that come with AI-assisted development — giving LLM tools codebase access, the OpenClaw skills marketplace vulnerabilities, and the kinds of security mistakes that are now much easier to ship without noticing.

George closes with practical advice for anyone hesitant to adopt agentic workflows: stay curious, ask the AI to explain the code it writes, build something outside your comfort zone, and put in the reps.

Resources Mentioned:
- Learn Phoenix Live View: https://learnphoenixliveview.com

Connect with George:
- X/Twitter: x.com/georgemillo
- LinkedIn: linkedin.com/in/millog

Sponsors:
- Paraxial.io — Elixir-first application security: paraxial.io
- Jido — Elixir AI Collective Discord: agentjido.xyz/discord

SUPPORT ELIXIR MENTOR
- Elixir Mentor: elixirmentor.com

Leandro Pereira is back on the Elixir Mentor Podcast — this time to dive deep into MDEx, his Rust-powered Markdown library for Elixir. MDEx is built on the Comrak Rust crate, runs 31x faster, and uses 3,500x less memory than existing Elixir alternatives. We also get into Lumis, his standalone syntax highlighting engine powered by tree-sitter and Neovim themes.

Leandro walks through why he chose a Rust NIF over a pure Elixir implementation, what it took to ship Lumis as its own project, and the surprisingly hard technical challenge at the heart of MDEx: streaming Markdown for AI applications. We discuss how MDEx handles incomplete Markdown fragments in real time, what the upcoming Components feature unlocks for Phoenix/LiveView developers, and how the HEEx parser integration works under the hood.

We also cover the human side of maintaining two solo open source projects: how Leandro prioritizes, uses AI to chip away at the backlog, and thinks about monetization. The conversation goes deeper into how the AI era has changed Markdown's role in the ecosystem, the pitfalls of vibe coding, and what it really takes to get an open source project noticed — including the uncomfortable truth that marketing matters more than most developers want to admit.

The episode closes with a wide-ranging conversation on developer growth — the Dunning-Krueger curve, making the mental shift from OOP to functional programming, and why Elixir feels easier once it finally clicks. A great listen for anyone building libraries, wrestling with Rust NIFs, or navigating open source in the Elixir ecosystem.

Resources Mentioned:
- MDEx: https://mdelixir.dev
- MDEx on Hex: https://hex.pm/packages/mdex
- Lumis: https://lumis.sh
- Lumis on Hex: https://hex.pm/packages/lumis

Connect with Leandro:
- X/Twitter: https://x.com/leandrocesquini
- GitHub: https://github.com/leandrocp/mdex

SPONSORS
- Paraxial.io: https://paraxial.io
- Jido (Elixir AI Collective Discord): https://agentjido.xyz/discord

SUPPORT ELIXIR MENTOR
- Elixir Mentor: https://elixirmentor.com

Josh Price, founder & CTO of Alembic and one of the core forces behind Ash Framework, joins me for a wide-ranging conversation that starts with the origin story of Alembic, winds through the history of GraphQL and Ash, and lands on Clarity — his new interactive introspection and visualization tool for understanding your Ash codebase. Josh has been writing Elixir for over ten years and building Alembic for nine, which gives him a rare perspective on how the ecosystem has matured and where it's headed in an agentic world.

We trace how Josh's frustration with real-time data at a gaming company pointed him toward Elixir and Erlang, how that led to an obsession with GraphQL domain modeling, and how that obsession eventually collided with Ash — which turned out to solve exactly the problems he'd been hacking around for years. We talk about what Ash actually is beyond an API generator, why auto-generated migrations are criminally underrated, and why the developers who resist Ash most are often the ones in the middle of the experience curve. Josh also shares the inside story of how slowing Zack Daniel down was actually the best thing that ever happened to the Ash ecosystem.

A big chunk of the conversation covers the AI moment we're in right now — Claude Code workflow tips (including the /insights command and how to keep session history beyond 30 days), why CLIs are beating MCPs for LLM tool use, Claude Code skills and usage rules for progressive disclosure, and how Clarity grew from Ash's built-in introspection into something far more interesting: an in-memory Erlang digraph knowledge graph of your entire Elixir application. Josh also shares his take on multi-model databases, the disappearance of the UI, and why the only limits left for software engineers are taste, judgment, and imagination.

Resources mentioned in this episode:
- Alembic: https://alembic.com.au
- Clarity (Hex): https://hex.pm/packages/clarity
- Ash Framework: https://ash-hq.org
- Ash Framework book: https://pragprog.com/titles/ldash/ash-framework/
- Killswitch: https://killswitch.app

Connect with Josh:
- Website: https://alembic.com.au
- X/Twitter: https://x.com/joshprice
- LinkedIn: https://www.linkedin.com/in/joshcprice

Sponsors:
- Paraxial.io: https://paraxial.io
- Jido: https://agentjido.xyz/discord

SUPPORT ELIXIR MENTOR
- Elixir Mentor: https://elixirmentor.com

Thomas Athanas, Head of Engineering at LevelAll, joins me on the Elixir Mentor Podcast to talk through the infrastructure, architectural, and leadership decisions that come with building systems you actually own — and what happens when vendor lock-in catches up with you in production.

Thomas walks through LevelAll's move away from Fly and Gigalixir toward bare metal hardware, the thundering herd problem that comes with serving 50,000 concurrent education users, and why they made the call to remove both Phoenix LiveView and Ash framework from production. We get into Ash APS premium support, JSONB query challenges, and the tradeoffs of leaning on a framework when hiring for it is hard.

We talk about using AI as a development planning tool and context keeper for managers — including Thomas's "Lore Master" concept, where AI agents preserve institutional knowledge so it never walks out the door. From there we get into the Auth0 rate limiting incident that hit during a live onboarding, the FusionAuth migration that followed, enterprise auth requirements like OIDC and SAML, and the bcrypt hash conversion work that made it all possible. Thomas also shares his work on a custom Erlang-based bare metal deployment agent and his approach to Postgres configuration and backups with pgBackRest.

The second half covers founder mode mentality, total ownership of problems, the player-coach leadership style, Sanity CMS vendor lock-in, building an audience vs. building a customer base, and practical advice for technical founders who keep procrastinating with features instead of making sales.

Connect with Thomas:
- X/Twitter: https://x.com/ThomasAthanas
- LinkedIn: https://www.linkedin.com/in/thomasathanas/

Sponsors:
- BEAMOps: https://beamops.co.uk
- Paraxial.io: https://paraxial.io
- Jido: https://agentjido.xyz/discord

SUPPORT ELIXIR MENTOR
- Elixir Mentor: https://elixirmentor.com/?utm_source=elixir-mentor

In this episode of the Elixir Mentor Podcast, I sit down with Amos King, Senior Staff Backend Engineer at Adobe, founder of Binary Noggin, and longtime Elixir community contributor. We dig into mentorship, knowledge sharing, and the team dynamics that make software organizations actually thrive.

Amos traces his non-traditional path into software — from structural engineering to manufacturing automation to Erlang on Navy submarines — and explains how that background shapes how he thinks about building reliable systems. We talk about his decade running Binary Noggin, why he ultimately made the move to Adobe, and the hard lessons learned when the consulting market shifted. From there the conversation goes deep on team composition, why diverse backgrounds matter more than uniform credentials, and the mindset shift from object-oriented to functional programming.

We also get into the practical side of Elixir: when GenServers are the right tool and when they're not, why vibe coding worries him from an engineering quality standpoint, and why teaching is actually a selfish act that benefits the teacher most. We close out with what separates a real staff engineer from a senior one, a call for the Elixir community to revive local meetups, and a real-world database query optimization story that reframes how to think about performance problems.

Resources Mentioned:
- Binary Noggin: https://binarynoggin.com

Connect with Amos:
- X/Twitter: https://x.com/Adkron
- LinkedIn: https://www.linkedin.com/in/amosking/

SPONSORS
- BEAMOps: https://beamops.co.uk
- Paraxial.io: https://paraxial.io
- Jido: https://agentjido.xyz/discord

SUPPORT ELIXIR MENTOR
- Elixir Mentor: https://elixirmentor.com

In this episode of the Elixir Mentor Podcast, I chat with Dave Lucia, CTO and Co-Founder of TV Labs. Dave returns to the podcast to talk about building an AI-powered smart TV testing platform that lets media companies test streaming apps on hundreds of real physical devices through the cloud — all built primarily in Elixir.

Dave walks through the founding of TV Labs, from meeting his co-founder at Bloomberg over a decade ago to building an MVP with WebRTC during the pandemic. He covers the technical challenges of managing a massive device lab — procurement, warm-up processes, security isolation, session management, and keeping hundreds of TVs, Rokus, Fire TVs, and Apple TVs healthy and available for enterprise clients. The platform uses a custom KQL query engine for real-time device matching and a licensing system built on Elixir GenServers sharded across the cluster.

We get into Dave's 10-year history with Elixir in production, starting at Bloomberg and carrying through to TV Labs. He explains why Elixir was the right fit for orchestrating physical devices at scale, from its standard library minimizing dependencies to building Apple device communication libraries and even a Lua 5.3 interpreter directly in Elixir. Dave also shares how TV Labs uses OpenTelemetry for observability and runs multi-region infrastructure with session recording capabilities.

The conversation shifts to AI, where Dave describes using Claude and other LLMs to accelerate development, automate operations like vendor management and support emails, and build AI agents for QA testing. We wrap up with a candid discussion on whether AI will replace developers and how these tools are fundamentally changing what's possible for small teams.

Connect with Dave:
- Website: https://davelucia.com
- X/Twitter: https://x.com/davydog187
- LinkedIn: https://www.linkedin.com/in/david-lucia-a395441b/

Sponsors:
- BEAMOps: https://beamops.co.uk
- Paraxial.io: https://paraxial.io
- Jido: https://agentjido.xyz/discord

SUPPORT ELIXIR MENTOR
- Elixir Mentor: https://elixirmentor.com

In this episode of the Elixir Mentor Podcast, I chat with Rob Walling — serial entrepreneur, author of The SaaS Playbook, founder of MicroConf, co-founder of TinySeed, and the guy who bootstrapped Drip to a successful exit. With over 20 years of experience and investments in 230+ B2B SaaS companies, Rob shares the playbook for building software businesses without venture capital.

Rob breaks down his stairstep method of entrepreneurship, explaining why technical founders should start with small wins on existing marketplaces before attempting a standalone SaaS product. We get into the common traps developers fall into — refusing to learn marketing, building products that "sell themselves," and bootstrapping two-sided marketplaces without an existing audience. Rob also shares the full Drip origin story, from a plateauing email tool to a marketing automation platform that took off after listening to customer feedback.

We cover the four core SaaS skills every founding team needs (marketing or sales, product, and engineering), how to decide between finding a co-founder and learning to sell on your own, and where successful SaaS ideas actually come from — 72% were discovered at a day job. Rob also weighs in on how AI is reshaping the SaaS landscape, why he doesn't believe in a "SaaS apocalypse," and what really drives company valuations. His final advice for technical founders: think in years, not months, and invest in learning entrepreneurship the same way you invested in learning to code.

Resources Mentioned:
- The SaaS Playbook: https://saasplaybook.com
- MicroConf: https://microconf.com
- TinySeed: https://tinyseed.com

Connect with Rob:
- Website: https://robwalling.com
- X/Twitter: https://x.com/robwalling
- LinkedIn: https://www.linkedin.com/in/robwalling
- Podcast: https://www.startupsfortherestofus.com

Sponsors:
- Paraxial.io: https://paraxial.io
- Jido: https://agentjido.xyz/discord

SUPPORT ELIXIR MENTOR
- Elixir Mentor: https://elixirmentor.com

In this episode of the Elixir Mentor Podcast, I chat with Jamil Bou Kheir, founder of Firezone, a YC-backed open-source zero-trust access platform. Jamil shares his journey from eight years as a Cisco security engineer to building an enterprise VPN replacement using Elixir and Rust.

We explore how Firezone started as a simple WireGuard configuration tool that hit the front page of Hacker News, then evolved into a full zero-trust platform. Jamil explains the architecture decisions behind using Elixir for the control plane and Rust for the data plane, including their custom ICE implementation called Snownet for NAT traversal. The conversation covers practical insights on Phoenix PubSub for real-time signaling, Postgres WAL streaming for change data capture, and running a global Erlang cluster.

Jamil also shares candid advice from the Y Combinator experience, discussing funding, product-market fit, and the challenges of rebuilding a product architecture mid-startup. We dive into the realities of open source licensing, security through transparency, and SOC 2 compliance. The episode touches on AI in development workflows, managing large refactors, and marketing strategies for technical founders.

Whether you're interested in networking protocols, building with Elixir at scale, or the startup journey from side project to funded company, this conversation offers valuable perspective from someone doing it in production.

Resources Mentioned:
- Firezone: https://www.firezone.dev
- WireGuard: https://www.wireguard.com
- Github: https://github.com/firezone/firezone

Connect with Jamil:
- Website: https://www.firezone.dev
- X/Twitter: https://x.com/jamilbk
- LinkedIn: https://www.linkedin.com/in/jamilbk/
- GitHub: https://github.com/jamilbk

Sponsors:
- Paraxial.io: https://paraxial.io
- Jido: https://agentjido.xyz/discord

SUPPORT ELIXIR MENTOR
- Elixir Mentor: https://elixirmentor.com

In this episode of the Elixir Mentor Podcast, I chat with Enrique Leigh, founder of Prende Café in Chile. We explore how he built a specialty coffee subscription business using Phoenix LiveView, his journey from marketing and ad tech to becoming an Elixir developer, and why he chose custom e-commerce over platforms like Shopify.

Enrique shares the WordPress crash during a Chile vs Brazil match that sparked his interest in Elixir, and how building his own coffee business became the perfect way to finally learn the language. We discuss UX principles from "Don't Make Me Think," marketing frameworks like Jobs to Be Done, and the counterintuitive lesson that adding more checkout steps can actually increase conversions. He also explains the specialty coffee value chain, from sourcing beans in Brazil to roasting and running a physical café alongside the e-commerce platform.

Our conversation covers practical entrepreneurship topics including MVP philosophy, building subscription and coupon systems with Mercado Pago, using Oban for job scheduling, and content marketing strategies that work. Enrique shares insights on balancing Iron Man training with running a family business, productivity techniques from the Flow Research Collective, and the evolving landscape of ad tech after GDPR. We also discuss his future goals of learning Nerves to build IoT coffee machines and the growing Elixir community in Chile.

The episode wraps up with advice for aspiring entrepreneurs: just launch it. Enrique emphasizes that the cost of inaction is often greater than the cost of action, and with tools like LLMs that work remarkably well with Elixir, there's never been a better time to build your own products.

Resources Mentioned:
- Don't Make Me Think: https://sensible.com/dont-make-me-think/
- Oban: https://getoban.pro/
- Jido: https://agentjido.xyz/discord

Connect with Enrique:
- Website: https://www.prendecafe.cl
- X/Twitter: https://x.com/EnriqueLeigh
- LinkedIn: https://www.linkedin.com/in/enriqueleigh/

Sponsors:
- Paraxial.io: https://paraxial.io
- Jido: https://agentjido.xyz/discord

SUPPORT ELIXIR MENTOR
- Elixir Mentor: https://elixirmentor.com