AI Pipeline Exception Handling: Hallucinations, Refusals, and Format Violations Are First-Class Errors
Your AI pipeline reported zero errors last night. The output was completely wrong.
That's not a hypothetical. A recent industry report found that roughly 1 in 20 production LLM requests fail in ways that never surface as exceptions — valid HTTP 200, well-formed JSON, fluent prose, factually wrong. The observability stack stays green while the pipeline quietly lies to its users.
The root cause is an architectural assumption borrowed from traditional service engineering: that HTTP status codes and parse errors cover the failure space. They don't. LLM pipelines have at least four failure types that the underlying infrastructure cannot see — hallucinations, refusals, format violations, and context overflow — and treating them as edge cases instead of first-class error types is how production AI systems ship invisible bugs at scale.
