---
title: "Stuff Goes Bad"
description: "The Heroku Routing team describes a manual created to preserve hard-earned operational knowledge from developing and maintaining Erlang systems at scale. That knowledge had typically been passed informally through incident simulations, code reviews, and similar practices, leaving no persistent record for new team members. The manual presents itself as a guide to being an “Erlang medic” during failures, combining tips, tricks, code snippets, and practices for understanding failure sources and debugging running production systems. It is available as a free PDF under a Creative Commons License at erlang-in-anger.com, and was released in time for the Chicago Erlang conference, where Routing team members and Erlang community participants could discuss real-world applications."
---

# Stuff Goes Bad

[Heroku](https://yomu.fyi/company/heroku) · Fred Hebert · Sep 17, 2014

**Type:** Announcement

## Summary

The Heroku Routing team describes a manual created to preserve hard-earned operational knowledge from developing and maintaining Erlang systems at scale. That knowledge had typically been passed informally through incident simulations, code reviews, and similar practices, leaving no persistent record for new team members. The manual presents itself as a guide to being an “Erlang medic” during failures, combining tips, tricks, code snippets, and practices for understanding failure sources and debugging running production systems. It is available as a free PDF under a Creative Commons License at erlang-in-anger.com, and was released in time for the Chicago Erlang conference, where Routing team members and Erlang community participants could discuss real-world applications.

## Context

The team wanted to preserve operational knowledge that was usually transmitted informally through incident simulations, code reviews, and related practices, rather than recorded persistently for new members.

## Approach / What changed

The manual collects tips, tricks, code snippets, and practices from Erlang production work to help developers operate, diagnose, and debug running systems.

## Takeaways

- The manual focuses on operational failures and debugging in production Erlang systems, rather than tutorial-level development alone.
- Its material includes code snippets and practices intended to help readers understand where failures come from.
- The free PDF is published under a Creative Commons License at erlang-in-anger.com.

**Tags:** [Debugging](https://yomu.fyi/topic/debugging), [Erlang](https://yomu.fyi/topic/erlang), [Reliability](https://yomu.fyi/topic/reliability)

- Source: [Heroku](https://www.heroku.com/blog/erlang-in-anger)
- Source URL: https://www.heroku.com/blog/erlang-in-anger
- Ingested by Yomu: 2026-09-09T14:23:29.838Z

[Read original post](https://www.heroku.com/blog/erlang-in-anger)