Senior devs used AI coding tools and got 19% slower. But they felt 20% faster. Read that again.
No, you read that correctly. A 39-percentage-point difference between what people think about something and what the truth is. And it might be the most important finding about AI-assisted development this year.
The Study
Experienced open-source developers who worked on real tasks were measured by researchers with and without AI coding assistants. They weren't juniors going through tutorials. These were seasoned contributors familiar with their codebases.
The outcome? These AI tools actually made them 19% slower. Those same developers self-reported feeling roughly 20% faster.
