3 Tests That Pass in LangFlow But Fail in n8n Production

You built a LangFlow prototype. Every test passed. You exported the flow, dropped it into n8n, and the first production run broke.

This is not a bug report. It is a pattern.

The three-year SDET who has built LangFlow prototypes but hit mysterious failures when deploying the same logic in n8n production already knows the feeling. The prototype felt solid. The production pipeline felt like a different language.

It is not. The difference is execution context. LangFlow runs in a notebook-like environment where state is forgiving and retries are invisible. n8n runs in a workflow engine where every node is a transaction boundary and every failure is final unless you explicitly handle it.

Here are the three tests that pass in LangFlow but fail in n8n production, and what they teach about building reliable AI pipelines.