What if no handler answers? Never approve

transcript

A payment goes down a chain of checks. Every check says, not mine. Pass it on. Then it falls off the end. And no one has said yes, or no.

The limit check has nothing to say. It passes the payment on. The fraud check has nothing to say either. And there is no bank at the end. Nobody has decided anything. The request just falls out of the last handler.

If the caller reads silence as yes, the payment is approved. Money moves, and no check decided. So fail closed. No answer is never approved. For anything that moves money, silence is not consent.

One way: end with a handler that always answers. The bank does. The other: return an explicit unhandled verdict, and treat it as no. Either way, the end of the chain is a decision.

End every chain with a decision. No answer is never yes.

Full breakdown in the lecture.