The CrowdStrike failure was the result of a buggy software update. The bug didn’t get caught in testing and was rolled out to CrowdStrike’s customers worldwide. Sometimes, failures are deliberate results of a cyberattack.

Imagine a house where the drywall, flooring, fireplace, and light fixtures are all made by companies that need continuous access and whose failures would cause the house to collapse. You’d never set foot in such a structure, yet that’s how software systems are built. It’s not that 100 percent of the system relies on each company all the time, but 100 percent of the system can fail if any one of them fails.