In many cases these system may process millions or billions of dollars of transactions a day. They may be a specification or there may not be and there are prob

In many cases these system may process millions or billions of dollars of transactions a day. They may be a specification or there may not be and there are probably a dozen corner cases that are not specified. Nobody wants to be the one who decided to replace it with a shiny kube cluster running node js or something and then have it all go up in smoke and losing money, customer, reputation.