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

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