AI Research | 7/15/2025

AI Paradox: Coding Assistants Slow Down Experienced Developers

A recent study reveals that experienced developers using AI coding assistants took 19% longer to complete tasks, contradicting their belief in increased speed.

AI Paradox: Coding Assistants Slow Down Experienced Developers

So, picture this: you’re a seasoned software developer, right? You’ve spent years honing your skills, diving deep into the intricacies of code, and you think you’ve got it all figured out. Then, someone tells you about this shiny new AI coding assistant that’s supposed to make your life easier. You think, “Great! This is gonna save me time!” But hold on a second—what if I told you that a recent study found that using these AI tools actually made experienced developers slower? Yeah, you heard that right.

The Study That Shook Things Up

Let’s break it down. This study, conducted by the folks at METR, a nonprofit focused on AI research, looked at how 16 experienced open-source developers fared when using AI coding assistants, specifically Cursor Pro, which is powered by models like Claude 3.5/3.7 Sonnet. These developers weren’t just any coders; they had an average of five years of experience working on popular open-source projects. They were tasked with tackling 246 real-world issues—think bug fixes and feature implementations. Sounds straightforward, right?

But here’s the kicker: on average, these developers took 19% longer to complete their tasks when they had the AI tools at their disposal. Before the study, they were convinced that AI would speed them up by about 24%. Even after the tasks were done, they thought they were 20% faster with AI. Talk about a reality check!

Why the Slowdown?

So, what’s going on here? Well, it turns out that the very expertise that makes these developers good at their jobs might also be what’s slowing them down. You see, they’re so familiar with their codebases that the AI’s suggestions often didn’t hit the mark. Imagine you’re a chef who knows every ingredient in your kitchen. If a robot chef suggests using basil instead of thyme for your famous pasta dish, you’re gonna raise an eyebrow, right? That’s kinda what happened here. The AI’s suggestions were often “directionally correct, but not exactly what’s needed.”

This forced the developers to spend time double-checking, correcting, and refining the AI-generated code. It’s like having to sift through a bunch of half-baked ideas instead of just cooking up your own masterpiece. And let’s not forget that some of these open-source projects have over a million lines of code! The AI tools struggled to grasp the full context and nuances of these massive codebases, leading to suggestions that were less than reliable. In fact, developers accepted less than 44% of the AI’s generated suggestions. Yikes!

The Bigger Picture

Now, here’s the thing: this study has big implications for the AI industry, which has been pushing the narrative that AI is a game-changer for productivity in software development. The findings suggest that the benefits of AI aren’t as universal as we thought. While previous studies showed productivity gains, they often used synthetic tasks that don’t really capture the messy reality of real-world software development.

But wait, don’t throw the AI tools out just yet! Despite the slowdown, many developers continued using these tools after the study. Why? Well, they found value in reducing cognitive load or just making the development process more enjoyable. It’s like having a friend help you brainstorm ideas, even if you end up doing most of the heavy lifting yourself.

Conclusion: A Nuanced Perspective

In the end, the METR study paints a more complex picture of AI in software development. For experienced developers working in familiar, complex environments, these AI coding assistants can sometimes hinder productivity rather than help it. The time spent verifying and correcting AI suggestions can outweigh the benefits of automated code generation. It’s a reminder that integrating AI into expert workflows isn’t as simple as flipping a switch.

And here’s a thought: maybe there’s a skill ceiling we haven’t considered. Learning how to effectively collaborate with an AI partner might be a skill in itself, one that takes time and experience to develop. As the AI landscape continues to evolve, understanding these nuances will be crucial for creating tools that truly enhance human expertise instead of getting in the way.

So next time you think about using an AI coding assistant, just remember: it might not be the magic bullet you hoped for, especially if you’re already a coding whiz!