One Writer · Our tools assume one writer, and assume that writer is a human. Nothing computes what a change reads and writes at runtime, so the only known fix is brute force priced for organizations.

In this blog post, I discuss three days in July 2026 when a single agent session ran away from me, and what those three days revealed about the concurrency assumptions buried in our development tooling. Six weeks ago I wrote The Test Suite Was the Incident : my test suite had grown a pile of shared data nobody owned, every pull request paid to rebuild it, and the resulting failures had nothing to…