The outage underscored a central trade-off of cloud computing: while it lets businesses deploy global services without maintaining vast infrastructure, it concentrates risk. A problem in a single region—like Northern Virginia—can cause widespread, simultaneous outages for unrelated companies worldwide.

Since a large portion of the internet depends on AWS, the outage cascaded across major firms in disparate industries, leaving some people unable to access airline information or make everyday purchases, Qi Liao, a professor of computer science at Central Michigan University, told ABC News.

Experts say the incident revealed what can happen when a such a broad spectrum of companies rely on singular cloud provider.

A Domain Name System error that originated from Amazon's largest and oldest data center took down major sites Monday. The outage has been resolved.

Is Amazon Web Services still down? What is AWS outage incident status? What we know on services affected or websites with issues like Canvas, Reddit and more.