I was in a conversation recently with a senior engineering leader at Microsoft. He mentioned, almost in passing, that their development teams now carry an internal target: generate 50% of production code using AI tools. Not a stretch goal. A target. I've been thinking about what that actually means for the working engineer — not the headline version, but the granular, day-to-day reality of what changes and what doesn't. What the 50% number is measuring First, let's be precise about what "50% AI-generated code" means, because the metric itself is underspecified. Is it 50% of lines committed? 50% of characters? 50% of files touched in a sprint? Does a human-edited AI suggestion count as 50% AI or 0%? At most orgs tracking this, "AI-generated" means code that was initially produced by a copilot or agent tool and accepted by the engineer — even if subsequently edited. On that definition, the number at many teams is already 30–40% for greenfield work.…