Half a century ago, I wrote my first program in COBOL. It was the beginning of my computing journey, and I never imagined that, in 2025, this language created in the 1950s would still be the backbone of the digital economy.
While Python, JavaScript, and Go dominate the headlines, COBOL continues to process trillions of dollars a day. Quietly, with the same reliability as ever.
In the 1950s, programming was chaotic. Each manufacturer had its own language, and changing machines required rewriting everything from scratch. That's when the US Department of Defense convened industry and academia to create a common, readable, and portable language. COBOL (Common Business Oriented Language) was born, with the brilliant Grace Hopper championing the idea that code should look like English, not math.
The result? A language any business analyst could read, which quickly became the universal language of corporate mainframes.
From the 1960s to the 1980s, COBOL reigned supreme in banks, governments, and large corporations. At its peak, 80% of the world's business systems were written in it. Today, in the midst of the AI era, the numbers are still impressive, with estimates indicating that between 220 and 850 billion lines of COBOL remain active. $3 trillion is processed daily using COBOL code, and 95% of ATMs and 80% of card transactions depend on it. In 2022, in the US alone, banks spent $36.7 billion maintaining legacy systems, a figure expected to exceed $57 billion by 2028!
What explains this longevity? Several factors, such as stability and performance: COBOL systems are robust and virtually immune to failure. The cost of replacement, since rewriting millions of lines is risky and extremely expensive, is high. And the embedded knowledge, when much of the business rules reside solely in these systems.
Far from being a museum piece, COBOL has evolved. Recent versions support object orientation, JSON, XML, and REST APIs. Today, it runs on hybrid clouds, communicates with Java, Python, and C#, and can be accessed via microservices. The trend isn't to erase COBOL, but to encapsulate, refactor, and integrate it, preserving decades of business logic with new digital layers.
COBOL doesn't grace the stages of tech conferences, but it holds the stage. And the fact that COBOL is still here, 65 years later, is perhaps the greatest testament to software engineering the world has ever seen.
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