Unhappy path
What happens when an AI system fails, is uncertain or meets a case it was not built for. A buyer should design and test it, because vendor demos show only the happy path.
The happy path is the sequence in which everything works: clean input, correct output, no exceptions. The unhappy path is everything else: ambiguous inputs, tool failures, wrong answers, missing permissions, a person who needs to take over.
Vendor demos are designed around the happy path, because success is the cheapest path through a system. That tells a buyer very little about operating the product. What decides cost and risk is how failure is detected, contained, reversed and handed back.
Make the buyer design it
In an evaluation, make the demo fail on purpose. Ask for a recovery contract, measure recovery distance and watch how much human attention the failure consumes. A failure test is also a supervision test. See AI procurement.
Read more in Make the AI vendor demo fail.
Related terms
Recovery contract
A short written artifact in an AI vendor evaluation that states how failures are detected, contained, reversed and handed back to people — and who is responsible at each step.
Recovery distance
The amount of human and system work needed to get from an AI failure back to a safe, correct state — a cost that belongs in the business case, not just the demo.
AI procurement
Buying AI products and services. A team cannot buy 'reasoning'; it buys a configured system with a route, harness and failure behavior, which is what the evaluation should test.
Used in these essays
Cahit Arf’s 1959 question about thinking machines
In a 1959 text on thinking machines, Cahit Arf moved from clocks and relays to a harder question: what happens when a machine meets a problem that was not anticipated when it was built?
Make the AI vendor demo fail
A polished AI demo proves that a system can succeed under prepared conditions. A buying decision needs different evidence: what happens when the system is wrong, blocked, uncertain or halfway through an action.
The next AI interface may never be seen
Agents are turning software capabilities into an interface of their own. The next enterprise design problem is deciding what should be callable, by whom, and under which boundaries.