This. COBOL is actually quite performant given what it has to deal with. To answer the OP’s question: when you have 2M lines of COBOL that processes thousands o

This. COBOL is actually quite performant given what it has to deal with. To answer the OP’s question: when you have 2M lines of COBOL that processes thousands of medical records or financial transactions per second, is critically important to the business, and essentially never fails, there is absolutely no incentive to ever replace that code. It doesn’t matter if it’s “out of date” or in an uncool language.