Why your AI agent works in the notebook and breaks in production

Every team I talk to has the same story. The LangChain prototype works. The impresses the stakeholders. Then someone asks when it ships -- and the real work starts. Deployment pipelines. Security review. Observability. Governance. Six months of infrastructure your team has to build before a single user sees the agent. Here is the part nobody talks about: AI agents show 63% variation in execution paths for identical inputs. Your unit tests are not broken. Unit testing just does not work for something that behaves differently every single run.