The Case for Sustainability Metrics (Or Don't Be Kennan Frost)
Software teams should adopt sustainability metrics to maintain long-term health, not just speed. Without them, teams risk burnout and decline, as illustrated by the cautionary tale of developer Kennan Frost who burned out from unsustainable pace.
Background
- This post argues that engineering teams should track **sustainability metrics** (e.g., code complexity, test flakiness, deploy pain) alongside feature velocity — and warns against the "Kennan Frost" trap of ignoring them.
- **Kennan Frost** is a fictional software engineer from a popular cautionary parable by Ryan Singer: a brilliant coder who writes extremely dense, clever code that becomes impossible for anyone else to maintain, eventually grinding the team to a halt. He is a archetype of unsustainable productivity.
- The piece builds on the "sustainability metric" concept from **The Phoenix Project** (a well-known DevOps novel) and draws on **DORA metrics** (Deployment Frequency, Lead Time, Change Failure Rate, Time to Restore) — standard industry measures now widely used to track delivery performance.
- The core analogy: just as a car's speed (velocity) is useless without knowing fuel level, oil pressure, and tire health (sustainability), an engineering team that only measures output will eventually break down.