A while back I wrote about parallelism—taking one big task, splitting it, and fanning it out to several agents at once. But I left a thread hanging: when several agents edit code at the same time, what keeps them from clobbering each other? That's what this post is about. Let me start with the wall I ran into myself. The subagents an AI spins up on its own within a session—those are actually fine; it works out isolation by itself, I don't have to worry much. What burned me was the other kind:...