Code examples in this post are available in five languages. Pick yours: The pattern I keep seeing An agent reads a function that takes a list and returns a list. It writes tests. They pass. The function fails in production because it depends on a global config and a database singleton the signature never declared. The agent had no way to know. This isn’t a model problem. Functional programmers solved it in the 1980s. I’ve shipped AI products for over a decade, and the trajectory is always the sa...