Why AI Struggles With Legacy Code and Institutional Knowledge

This article argues that while AI significantly accelerates new code development, it does little to address the deeper challenge of maintaining and modernizing legacy systems. These systems rely heavily on institutional knowledge that often no longer exists, making them difficult to understand, debug, or safely modify. The real bottleneck in software engineering isn’t writing code—it’s untangling decades-old systems where context has been lost, creating systemic risk across industries.