COBOL, a language first introduced in 1959 by Grace Hopper (‘Grandma COBOL’), still processes 90 per cent of the planet’s financial transactions, and 75 per cent of all business data. You can make a comfortable living maintaining code in languages like COBOL, the computing equivalents of Mesopotamian cuneiform dialects. These ancient applications—too expensive to replace, sometimes too tangled to fix or improve—run on, serving up the data that appears on the chromed-up surface of your browser, which gives you the illusion that your bank and your local utility companies live on the technological cutting edge. But as always, the past lives on under the shiny surface of the present, and often, it is too densely tangled to comprehend.