How Meta is Using a New Metric for Developers: Diff Authoring Time

Diff Authoring Time (DAT), developed by Meta engineers, measures the duration from starting a code change to submission. By integrating with version control systems and IDEs, DAT provides insights into development efficiency without compromising privacy. This metric has helped Meta evaluate productivity improvements, such as a 14% authoring time reduction from a new mocking framework and 33% improvement from automatic memoization in React. DAT enables data-driven decisions to enhance engineering workflows and supports continuous improvement in software development practices.