But many engineering teams are noticing a trend: even as individual developers produce code faster, overall project delivery timelines are not shortening. This isn't just a feeling. A recent METR study found that AI coding assistants decreased experienced software developers' productivity by 19%. "After completing the study, developers estimate that allowing AI reduced completion time by 20%," the report noted. "Surprisingly, we find that allowing AI actually increases completion time by 19%-AI tooling slowed developers down."