AI Research | 7/12/2025
Developers Slower With AI Coding Tools, Despite Feeling Faster
A new study reveals that experienced developers are actually 19% slower when using AI coding assistants, even though they believe they’re working faster. This paradox raises questions about productivity measurement in the age of AI.
The Paradox of AI Coding Tools
So, picture this: you’re a seasoned developer, knee-deep in a complex open-source project. You’ve got your coffee, your favorite playlist, and now, you’ve got an AI coding assistant at your fingertips. Sounds like a recipe for productivity, right? Well, hold that thought. A recent study by METR, a nonprofit focused on AI research, has thrown a bit of cold water on that idea.
The Study That Shook Things Up
In this study, 16 experienced developers were observed as they tackled 246 real tasks within their own large-scale projects. They were using popular AI tools like Cursor Pro, powered by models such as Claude 3.5. Now, you’d think that having an AI buddy would speed things up, but here’s the kicker: these developers were, on average, 19% slower when using these tools. Yep, you heard that right!
But wait, it gets even more interesting. Before diving into the study, these developers were convinced that the AI would make them 24% faster. And even after realizing they were slower, they still felt like they were making progress—reporting a 20% perceived speed improvement. Talk about a disconnect!
What’s Going On Here?
So, what’s behind this puzzling phenomenon? Well, it turns out that the cognitive load of managing AI-generated code is no joke. Developers spent less time actively coding but more time prompting the AI, waiting for its output, and—most importantly—reviewing and cleaning up the AI’s suggestions. In fact, they dedicated about 9% of their time just to reviewing the AI’s work.
Imagine you’re in a race, but instead of running straight to the finish line, you keep stopping to check your GPS, recalibrating it every few minutes. Frustrating, right? That’s kinda what these developers were experiencing. Less than 44% of the AI’s suggestions were accepted, mainly because the AI didn’t quite grasp the context of the complex codebases they were working with.
The Hidden Costs of AI
This brings us to a term that’s been floating around: AI-induced tech debt. It’s like when you take a shortcut that seems faster but ends up costing you more time in the long run. The time spent validating and integrating AI-generated code can easily outweigh any time saved during the initial coding.
But here’s the twist: despite the measurable slowdown, developers reported feeling that their work was easier and more enjoyable with AI. It’s like when you’re playing a video game and you get a power-up that makes you feel invincible, even if you’re not actually progressing faster. This feeling of ease can be a powerful motivator, which might explain why many developers still want to use these tools, even after seeing the data.
Rethinking Productivity Metrics
This whole situation raises some serious questions about how we measure productivity in the age of AI. Sure, task completion times are important, but what about cognitive load, code quality, and long-term maintainability? It’s like trying to judge a movie solely by its box office numbers without considering the plot, acting, or cinematography.
While some studies have shown that AI tools can significantly boost productivity—especially for less experienced developers or simpler tasks—the METR research suggests that these benefits don’t necessarily apply to seasoned pros working in familiar environments.
What Does This Mean for the Future?
The implications of these findings are huge for the software development industry, which is rapidly adopting AI tools. The hype around massive productivity gains is real, but this study serves as a reality check. The true value of AI assistants might not just be about speed; it could be about alleviating cognitive burdens, improving job satisfaction, or even helping with repetitive tasks like boilerplate code.
As AI continues to evolve, it’s crucial for developers to focus on integrating these tools with existing codebases and minimizing the verification overhead. The industry needs to move beyond a simplistic view of productivity and develop a more nuanced understanding of how these powerful tools can enhance the craft of software engineering, rather than just speeding it up.
So next time you’re coding with an AI assistant, remember: it might feel like you’re flying, but sometimes, it’s all about the journey, not just the destination.