Every time you swipe a card at an ATM, there’s a good chance some of the code behind it runs on COBOL, a programming language from 1959. That’s not because banks are lazy. It’s a lesson about old business software, and it applies to your business too, even if the oldest thing you run is a spreadsheet from 2012.
Here is the quick version.
Why banks never replaced COBOL
A committee of computer makers and government experts designed COBOL in 1959 to handle business records: accounts, payroll, transactions. It turned out to be very good at that job. Banks built their core systems on it in the 1960s and 70s, and those systems kept working. A widely cited 2017 Reuters report estimated that COBOL still handled about 95% of ATM card swipes in the US.
So why not rewrite it? Because the code works, it moves real money every second, and nobody remembers every rule buried inside it. Rewriting a system like that is expensive and risky. One missed rule can mean wrong balances for millions of people. For a lot of banks, keeping the old code running is the safer bet.
The catch: old code needs people who know it
The trouble shows up when something has to change fast. In 2020, when unemployment claims spiked, some state agencies running COBOL systems put out public calls for COBOL programmers. The software wasn’t broken. There just weren’t enough people left who could change it quickly.
Then there’s Y2K. Lots of old systems stored years as two digits to save memory, so 2000 would read as 1900. Fixing that before the deadline cost businesses and governments hundreds of billions of dollars. We made a short video on the Y2K bug too. It’s a good example of a small shortcut that sat quietly for decades and then came due all at once.
Your old business software has the same problem
You probably don’t run COBOL. But you might run:
- A spreadsheet one person built years ago that the whole office depends on
- A booking or invoicing tool that hasn’t had an update in years
- An app a freelancer built that nobody else knows how to change
- A “temporary” workaround that is now five years old
Those are your COBOL. They work fine, until the one person who understands them leaves, the vendor shuts down, or you need them to do one new thing.
Old business software: patch it, wrap it, or rebuild it
When old business software starts to hurt, you have three real options.
Patch it. Fix the specific thing that’s broken and leave the rest alone. This is best when the system mostly works and the problem is small. It’s the cheapest option, but it doesn’t remove the bigger risk.
Wrap it. Leave the old system in place and build something modern around it, like a new screen, an API or an automation that pulls data out of it. This is what many banks actually do. The COBOL core keeps running, and the nice app on your phone talks to it. It’s best when the core logic is solid but people hate using it.
Rebuild it. Start fresh. This is best when the old system is blocking growth, can’t be kept secure, or costs more to keep alive than to replace. It’s the biggest project, so do it on purpose and with a plan, not in a panic.
What tech debt really costs
“Tech debt” just means shortcuts you pay for later. You pay it in slow work, when staff do workarounds every day. You pay it in risk, when only one person knows how something works. And you pay it in missed chances, like not being able to add online booking because the old system won’t allow it.
Here’s a simple test. Add up the hours your team spends each week working around the old tool, then multiply by 52. That’s roughly what the debt costs you every year, before anything even breaks.
A simple way to check your old business software
- Write down every tool your business can’t run without.
- Next to each one, write who knows how it works. If the answer is one person, or nobody, that’s your first priority.
- Decide for each one: leave it, patch it, wrap it, or plan a rebuild.
You don’t have to fix everything this year. You just don’t want to find out the hard way, the way those agencies did in 2020.
Built by Buit is a Florida AI and app studio. If you’re stuck with old business software nobody can maintain, our app rescue service is the place to start. If you’re weighing a rebuild, read custom software vs off the shelf first, or see what goes into custom app development.
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