A pull request lands. Two approvals, tests green, CI blue. It ships on a Tuesday.
Three weeks later there's an incident. Somebody opens the file and finds a branch nobody remembers discussing. It handles a rare case, and handles it wrong. You ask the author what it's for. They squint at it. They wrote it. They can't tell you why.
This isn't a story about a bad engineer. Every engineer I know has been that author, including me. The code I understand least in anything I ship is the code I generated fastest, and it is almost always the code furthest from the domain I'm strongest in. On my home turf a bad suggestion smells wrong immediately. Two directories over, it just looks like code.
So we get faster and we understand less, and the two facts don't feel connected because they show up in different places: velocity on a dashboard, confusion in a postmortem, six weeks apart.
They're connected.
