Trying to fill out an unemployment claim online but the site keeps crashing? The Verge is out with a great explainer on why. Here's the gist.
Back in the 1950s, government agencies and universities ran their own siloed computer networks with their own set of unique rules. Then, engineers created the Common Business Oriented Language (COBOL) so that these systems could talk with one another. COBOL runs everything off an organization's own handful of internal servers and is competent under normal circumstance. But if one goes down due to an unprecedented surge in traffic, the whole system crashes.
Netflix and other modern websites that see tens (or hundreds!) of millions of daily users are hosted on cloud infrastructures like Amazon Web Services (AWS), which uses a galaxy of servers located all over the world and can switch on and off based on demand. They are more or less disposable, so if one goes down, traffic is just diverted to another without users even noticing the difference. Unfortunately, you can't just switch from a COBOL infrastructure to AWS. The whole system has to be built from scratch which is expensive (taxpayers hate that) and the reason why COBOL has endured for so long.