Greg Mefford

Nerves Core Team and Spandex Core Team

Greg has always had a passion for metrics and monitoring. When he joined Bleacher Report, he had the opportunity to use the Spandex library to collect distributed trace data and visualize it using Datadog APM.

Since then, he has joined the Spandex project as a core maintainer, with the goal of supporting various vendor-specific back-ends with a vendor-neutral collection API.

He is also a core maintainer of the Nerves project for building BEAM-based embedded devices.

Past Activities

Greg Mefford
Code BEAM STO 2019
16 May 2019
17.15 - 17.40

Continuous tracing in production (without Erlang's trace module)

Collecting trace data from your application is a very important, but often overlooked, aspect of Application Performance Monitoring (APM). In this talk, we will learn about the core concepts of application tracing (OpenTracing and OpenCensus), some of the tools that are available for collecting and visualizing trace data, and how this data can be used for troubleshooting errors and performance issues, in both monolithic and distributed micro-service architectures.


  • Introduce the concepts of application tracing and the state of the ecosystem (Spans, Traces, Context Propagation, OpenTracing, OpenCensus, etc.)
  • Explain how this is different and complementary to Erlang's built-in trace module
  • Show what insights can be more easily gained from trace data as opposed to logs and metrics
  • Give an overview of the tools and vendors available to start using this technology today Show how to instrument Elixir-based application code using Spandex
  • Demonstrate how to explore the resulting trace data using Datadog APM to troubleshoot error and performance problems


Developers who are responsible for tracking down errors or performance issues, especially in a distributed micro-service architecture


Greg Mefford
Code BEAM STO 2018
31 May 2018
17.15 - 17.40

Embedded Elixir with Nerves

Nerves makes it very easy to leverage the BEAM in an embedded device using readily-available and low-cost hardware like the Raspberry Pi family of single-board computers. In this talk, we will cover the basics of what Nerves is and how to structure your application for easier testing without needing real hardware.


Understand what Nerves is, be ready to begin a project with Nerves.