The Biggest Problem With AI-Generated Code Isn't Bad Code. It's Unfamiliar Code.

A developer opens a pull request. The feature works. The tests are green. The implementation looks reasonably clean. Then they realize the PR changes 17 files for what should have been a relatively small feature. There is a new abstraction nobody on the team has seen before. A dependency has been added for functionality the project already had. Two similar utilities now exist in different parts of the codebase. The tests are extensive, but nobody is completely sure what assumptions they are actually testing. And the author didn't write most of it manually. AI did. This is one of the less obvious problems created by AI coding tools. The problem isn't necessarily that AI generates bad code. Sometimes it generates perfectly valid code. The problem is that it can generate code faster than a team can develop an understanding of it. That changes the bottleneck in software engineering. The Cost of Writing Code Has Changed For a long time, engineering teams were constrained by how quickly developers could implement things. A developer had to understand the requirement, design the solution, write the code, debug it, and test it. AI changes the economics of that process. A developer can now describe a feature, generate an implementation, ask for tests, refactor it, and generate supporting code in a fraction of the time it might previously have taken. That's useful. But the amount of code entering the system can increase faster than the team's ability to review and understand it. Consider a simple feature that requires modifying four files. An AI coding assistant might produce a solution that touches twelve. It may introduce a service layer, a helper abstraction, a configuration object, several interfaces, and a new package. None of these things are necessarily incorrect. But every additional abstraction creates another thing a future developer has to understand. This is where code familiarity becomes an engineering concern. Working Code Isn't the Same as Understandable Code A