What caused the AWS outage - and why did it make the internet fall apart?
Amazon Web Services (AWS) had a bad day.
That's how the boss of another big US tech firm Cloudflare put it – probably feeling very relieved that Monday's outage, hitting over 1,000 companies and affecting millions of internet users, had nothing to do with him.
The places hit by the outage vary significantly. It took out major social media platforms like Snapchat and Reddit, banks like Lloyds and Halifax, and games like Roblox and Fortnite.
AWS is a US giant with a large global footprint, having positioned itself as the backbone of the internet.
It provides tools and computers which enable around a third of the internet to work, it offers storage space and database management, it saves firms from having to maintain their own costly set-ups, and it also connects traffic to those platforms.
That's how it sells its services: let us look after your business's computing needs for you.
But on Monday, something very mundane went very wrong: a common kind of outage known as a Domain Name System (DNS) error.
People who work in the tech industry will be rolling their eyes right now.
This common error can cause a lot of havoc.
"It's always DNS!" is something I hear a lot.
When someone taps an app or clicks a link, their device is essentially sending a request to be connected to that service.
DNS is supposed to act like a map, and on Monday, AWS lost its bearings – platforms like Snapchat, Canva and HMRC were all still there but it couldn't see where they were to direct traffic to them.