On 20 October 2025 a fault in Amazon Web Services’ Northern Virginia region knocked apps, banks and online shops around the world offline for hours. What happened and what it teaches.
In the early hours of 20 October 2025, US East Coast time, Amazon Web Services’ us-east-1 region in Northern Virginia began to suffer cascading errors. For much of the day, thousands of services running on Amazon’s cloud were down or degraded around the world, including in Europe, where the outage coincided with the working morning.
What happened
According to Amazon, the root cause was a name resolution (DNS) problem that prevented applications from finding one of its database services, DynamoDB, in that region. Because many other AWS services depend on it, the error spread. Amazon fixed the underlying problem within a few hours, but full recovery, including the backlog of pending tasks, took until the evening.
Messaging services, social networks, video games, payment platforms, airlines, some British banks and Amazon’s own services, such as its online shop and smart speakers, were affected. Many companies that did not know they depended on that region found out that day, through one of their suppliers.
Why it matters
Three companies, Amazon, Microsoft and Google, hold most of the global cloud market. Concentration brings advantages of scale, security and cost, but it also creates single points of failure: when one goes down, it takes thousands of customers with it. A year earlier, in July 2024, a faulty CrowdStrike update had frozen millions of Windows computers.
In Europe, the DORA regulation, which has applied to financial firms since January 2025, requires them precisely to manage the risk of critical technology providers, and the NIS2 directive extends similar obligations to other sectors.
What to review
It is worth knowing which cloud providers the business depends on, directly or indirectly, and in which regions; what happens if one goes down for hours; and whether critical services can run from another region or under a fallback plan. It is also worth checking what contracts say about guaranteed availability and compensation, which is usually modest.
A continuity plan that has never been tested is just a document. Ask your technology lead whether yours covers the failure of a major provider.
The cloud is nowhere, but when it fails it is felt everywhere.
This article is general information. It is not legal, tax or investment advice, and it does not take anyone’s particular circumstances into account.
