A user analyzed the impact of AI on code generation and QA, suggesting that dedicated testers are necessary to maintain code quality. They propose integrating better QA processes to handle increased code volume generated by AI tools.
Hi. I've been a dev for 7 years. I worked on an enterprise project where management adopted AI tools aggressively but cut dedicated testers on new features. Within some months the codebase was unrecoverable and in perpetual escalation. I wanted to understand why, so I built a model and validated it on 27 public repos (FastAPI, Django, React, Spring Boot, etc.) plus that enterprise project. About 1.6 million file touch events total. Some results: * AI increases gross code generation by about 55%, but without QA the net delivery velocity drops to 0.85x (below the pre AI baseline) * Adding one dedicated tester restores it to 1.32x. ROI roughly 18:1 * Unit tests in the enterprise case had the lowest filter effectiveness of the entire pipeline. Code review was slightly better but still insufficient at that volume * The model treats each QA step (unit tests, integration tests, code review, static analysis) as a filter with effectiveness that decays exponentially with volume Everything is open access on Zenodo with reproducible scripts. [https://zenodo.org/records/18971198](https://zenodo.org/records/18971198) I'm not a mathematician, so I used LLMs to help formalize the ideas into equations and structure the paper. The data, the analysis, and the interpretations are mine. Would like to hear if this matches what you see in your pipelines. Especially interested in whether teams with strong CI/CD automation still hit the same wall when volume goes up.