Programming’s Greatest Mistakes by Mark Rendle

The Y2K bug wasn’t originally a mistake but a practical limitation due to expensive memory in the 1950s-60s. It cost around $500 billion to fix in the 1990s

The Ariane 5 rocket explosion ($580M loss) was caused by reusing code from Ariane 4 without proper adaptation - the 16-bit vs 32-bit integer conversion caused an overflow

The Mars Climate Orbiter crashed due to a units mismatch between imperial (pound-force seconds) and metric (Newton seconds) measurements - highlighting the importance of standardization

The Knight Capital trading disaster ($440M loss) happened when code deployment went wrong across servers, with no proper controls or limits on algorithmic trading

Null references, invented by Tony Hoare for ALGOL-W, are considered a “billion dollar mistake” that continues to cause problems in modern programming

JavaScript was created in just one week, leading to quirks and inconsistencies that still affect web development today

Infrastructure as code and automated deployments have made programming mistakes potentially more catastrophic, capable of taking down entire data centers

Copy-pasting code without proper understanding/adaptation remains a common source of serious bugs

The Hartford Center roof collapse ($90M) occurred because the CAD software only accounted for vertical snow load forces but not lateral ones

Modern agile/scrum methodologies and “enterprise” development processes often work against core software engineering principles and make development more difficult