One Brain, Two Front-Ends: Refunded Twice on Sale Day
On the first day of the big sale, a user requested one refund — and the refund service ran it twice. The money went out twice. In 10 minutes you'll be able to name, in an architecture review, the place a multi-agent system most loves to leak money: know to put an idempotency key on the layer two front-ends share, to ask 'is refundType defined the same in both systems,' and to see that the real bottleneck of multi-agent delivery is which team nods, not model quality.
Jul 6, 2026·12 min read