Paul GrahamVerified account

2/ "Over 80% of in-person transactions at U.S. financial institutions use COBOL. Fully 95% of the time you swipe your bank card, there’s COBOL running somewhere in the background."

3/ "The Bank of New York Mellon in 2012 found it had 112,500 individual COBOL programs, constituting almost 350 million lines; that is probably typical for most big financial institutions."

4/ "No one quite knows how much COBOL is out there, but estimates suggest there are as many as 240 billion lines of the code quietly powering many of the most crucial parts of our everyday lives."

5/ "The sheer age of those COBOL systems is, oddly, actually something that works in their favor. Because they’re old, they have been relentlessly debugged. When a program is first written, it inevitably has problems. Sometimes it’s a typo, a misplaced command; other times.."

6/ "...the user does something the programmer never expected, and things crash. When you get a new app, if it’s buggy and crash-prone, this is why: the creators sent it out into the world with lots of little flaws. It can take days, weeks, or years to discover all the problems."