How does complexity affect developer productivity?

Software complexity remains a critical topic for engineering teams aiming to maintain productive, sustainable codebases, although the correlation between complexity and productivity is challenging to establish due to varying definitions and measurement difficulties. The blog post explores different complexity metrics, such as cyclomatic and cognitive complexity, which quantify aspects of code difficulty, and it highlights the nuanced relationship between these metrics and productivity. While complex code is generally believed to hamper productivity, proving this link is complicated due to the subjective nature of productivity measurement, confounding variables, and the inherent complexity of some tasks. Although some research indicates correlations between complexity metrics and defect rates, a direct impact on overall developer productivity remains elusive. The blog suggests that engineering teams focus on understanding how complexity affects specific development activities, such as code comprehension and defect rates, rather than seeking a universal link between complexity and productivity. Complexity metrics should be used as signals for investigation rather than strict limits, serving as trending indicators to prevent technical debt from impeding development velocity. The post recommends prioritizing DORA metrics to identify real bottlenecks and considering complexity metrics as a secondary tool to address specific challenges, maintaining perspective on their role within broader engineering efforts.