It was perhaps the most widely tracked coupon payment in history.

After the Russian Finance Ministry on Monday sent an order initiating a $117 million payment due on dollar-denominated bonds this week, traders and money managers globally watched with bated breath as the money began to snake its way through the financial system.

What should normally be a quick formality between a borrower and its investors became an excruciating wait, as JPMorgan Chase & Co. and Citigroup Inc., the banks appointed to move the money, added extra diligence to the procedural steps amid punishing Russian sanctions. The lull left the world wondering if the country would make good on its debt — and heaped attention on a part of banking rarely in the spotlight: The staid back-office mechanisms that handle trillions of dollars of payments daily.