AI Shifts Software Bottlenecks as Study Found Developers Took 19% Longer
Updated
Updated · O'Reilly Media · Jul 16
AI Shifts Software Bottlenecks as Study Found Developers Took 19% Longer
3 articles · Updated · O'Reilly Media · Jul 16
Summary
METR’s early-2025 experiment found open-source developers using AI tools took 19% longer, even as they believed they were about 20% faster—highlighting a sharp perception gap.
By late 2025 and 2026, AI appeared more helpful, but measurement broke down: METR abandoned a follow-up after developers refused non-AI tasks, while self-reported gains rose to 1.4x-2x.
Operational data suggests the gains are moving upstream rather than speeding delivery. CircleCI’s analysis of 28 million workflows showed throughput up 59%, but median main-branch throughput fell 7% and build success dropped to 70.8%.
Other studies point to the same mechanism: Anthropic engineers reported a 50% boost and 67% more pull requests, while HBS found workers outside their expertise still underperformed domain experts by 13% on execution.
The article argues AI makes coding, tests and scaffolding cheaper but shifts constraints to review, verification, security and CI, making ship-time metrics—not PR counts or engineer sentiment—the better test of productivity.
Why does AI make developers feel 20% faster when they are actually 19% slower?
Must companies now reinvent their entire engineering culture to truly benefit from AI?
AI Coding Tools in 2026: Measuring Real Productivity, Risks, and the $10B Enterprise Market Shift
Overview
By mid-2026, the AI coding tools market has rapidly evolved, with enterprise AI coding agents now capturing a significant share of software engineering spending and reaching a market value of up to $11 billion. This growth reflects major advances in AI capabilities over the past five years, fundamentally changing what these tools can achieve. However, the fast pace of innovation has created a dynamic and unpredictable environment, making it challenging to forecast future developments. As new players enter this crowded sector, organizations must adapt quickly to leverage AI's potential while navigating ongoing changes and uncertainties.