Why COBOL Is Still Around

Although the most popular computer languages are relatively modern, like JavaScript, C#, C++, Go, and PHP, many of the world's largest financial systems run on COBOL, which has been around since the 1960s. There are good reasons for that, as this article points out. 

There are an estimated 240 billion lines of COBOL out there, and they're the backbone of your financial life — 95% of the time when you swipe your bank card, there's COBOL involved, and every night when the work-day is over, the massive mainframe farms of big banks leap into action, using COBOL to balance the day's books.

Why is COBOL — which debuted in 1969 — still so crucial to everyday life? The online finance magazine Wealthsimple asked me to write about that, so I talked to tons of COBOL folks, including some programmers who wrote bank routines in the 1980s that are still being used today — they're long retired, in their 70s, and their banks still call them up to ask them to maintain the stuff.

There are lots of reasons COBOL's still around, but one that's intriguing is that three-decade-old code is stable as hell. You have code in production that long, it's been debugged within an inch of its life; and they've had decades to tweak the compilers — which turn the COBOL into instructions for the machine — for massive efficiency.

This turns the new-new-thing hype of Silicon Valley on its head, of course. It's a sector obsessed with the hottest, latest thing — but as any programmer can tell you, the hottest, latest thing that just got shipped at 2 am is gonna be a rickety kluge of buggy code. That old COBOL, though? In service since the days of early MTV? It's tough as old boots.

During my time as a technical writer, I've been involved in several projects that aimed to either replace COBOL code, or bolt on a snazzy new front end written in the hot language of the day. Guess what. That legacy code is still running, although the mainframe may have been replaced by more modern hardware and the front-end software has been rewritten or replaced several times.