Does AI really make developers faster?
A field study (METR, 2025) found that experienced engineers actually got 19 % slower when allowed to use tools like Cursor + Claude 3.7.
They expected a 24 % boost. They felt 20 % faster.
Reality: slower code, more review, more waiting.
Why?
AI can’t grasp hidden repo knowledge.
Experts already know better patterns.
Only 44 % of AI code was usable without heavy cleanup.
Large, mature projects confuse models.
And — most dangerously — it feels productive, so we overuse it.
Still, the story isn’t all downside — there are areas where AI genuinely adds value. It shines in small greenfield builds, documentation, and test generation, where human oversight adds polish instead of rework.
For consultancies and outsourcing teams, that means: stop selling “AI-acceleration”. Sell AI-alignment -- using it where it truly works.
AI doesn’t make you faster. It just makes you feel faster. And that’s fine — as long as you know the difference.