AI Wrote Half My Codebase. The Maintenance Bill Showed Up in Month Three.

The useful part

The bill arrived later, not in dollars, in the parts of the system nobody on the team fully understood anymore. I've shipped more open-source projects in the last few months than in years prior, and a lot of that is leverage. We've gotten very good at measuring the first draft and very bad at measuring what comes after it, and the after is where the actual cost lives.

How it works

• Just an accumulation of code that looked more trustworthy than it was, sitting in places that later changes had to work around.
• The bug that changed how I read AI code The moment that stuck with me wasn't a fire.
• The ratio that should worry you Every stage of the development cycle used to have roughly proportional cost.
• You wrote code, you reviewed code, you maintained code, and those costs were in the same order of magnitude.

What to take from it

Maintenance didn't move at all, and maintenance is the longest phase of any codebase's life. So we get a new shape: projects that look extremely productive in week one and increasingly expensive in month three. It's the pattern I keep seeing across the tools I've shipped this year, and it's slow.

Details worth keeping

The economics were stable enough that you could reason about them. It was a small bug in a very clean-looking change. The code read well, the tests passed, the comments looked thoughtful.