Introduction to Code Churn

When engineering leaders can clearly visualize progress, identify bottlenecks, and watch trends across multiple teams, they can notice when something’s off before a deadline is missed. They can experiment with meeting structure and timing, provide actionable feedback, and stay out of the details that should be handled at other levels. Then, they can measure the impact of those decisions.

Among the metrics that managers can use to understand a team’s progress is Code Churn. Code Churn is when a developer re-writes their own code shortly after it has been checked in (typically within three weeks). It’s typically a natural part of an engineer’s workflow as they explore, test, and refine their work — but unusually high levels of churn or unexpected fluctuations in the metric can be used as a signal that something’s off.

Watching trends in code churn can help managers notice when a deadline is at risk, when an engineer is stuck or struggling, or when there are issues concerning external stakeholders.

In this guide, we’ll unpack what code churn is, what it isn’t, and what to do when you notice an unexpected spike in the metric.