AWS said the problem started after temperatures rose inside a single data centre, blaming a cooling system failure while explaining that engineers brought extra cooling capacity online as recovery work continued.

The outage affected services in one Availability Zone, which is a group of connected data centres designed to operate separately within an AWS region. AWS said it redirected traffic away from the affected zone for most services to reduce disruption.

Later in the day, recovery was taking longer than expected because more cooling capacity was still needed before remaining systems could safely return online. AWS further added that it did not yet have a timeline for full recovery.

Coinbase confirmed its trading platform issues were directly linked to the AWS outage. Users reported problems accessing services and delays during trading, although the company later said all markets had been restored and trading resumed normally.

Meanwhile, CME Group reported login and latency problems on its CME Direct trading platform. In a notice to users, the exchange said it had completed “essential maintenance work” and confirmed customers could log back in. The company did not explain the cause of the disruption.

Neither AWS nor CME immediately responded to requests for additional comment outside normal business hours.

The incident again exposed how heavily large financial platforms depend on cloud providers such as AWS. Even a problem in a single data centre zone can spread quickly across trading services, apps and online platforms used worldwide.

AWS has faced similar problems before. In October last year, a major outage disrupted thousands of websites and apps, including Snapchat and Reddit. That disruption became one of the largest internet outages in recent years.

A month later, CME Group experienced another major interruption after cooling systems failed at a data centre operated by CyrusOne in the Chicago area. Trading across stocks, bonds, commodities and currencies stopped for several hours.

The latest outage also points to stress on data centres as companies expand artificial intelligence systems and use more high-density servers, which generate far more heat and demand stronger cooling systems.

AWS has advised customers to spread workloads across multiple Availability Zones and regions to reduce the risk of large-scale disruptions when outages happen.

The disruption, which originated from AWS’s US-EAST-1 data centre in Ashburn, Virginia, lasted several hours and left millions of users unable to access services such as Snapchat, Reddit, Venmo, Zoom, and even Amazon’s own Prime Video and Alexa. 

According to outage tracking site Downdetector, more than four million users globally reported problems during the incident.

By 3:01 p.m. PT (10:00 p.m. GMT), Amazon confirmed that “all AWS services returned to normal operations. Some services such as AWS Config, Redshift, and Connect continue to have a backlog of messages that they will finish processing over the next few hours.”

Root Cause: Network Health Monitor Failure

AWS identified the source of the failure as a malfunction in a subsystem that monitors the health of its network load balancers, a key component responsible for distributing traffic across multiple servers. 

The fault within its Elastic Compute Cloud (EC2) network also triggered a Domain Name System (DNS) error that prevented apps from locating DynamoDB, one of AWS’s most critical database services.

The outage, Amazon confirmed, “originated from within the EC2 internal network,” once again placing focus on the US-EAST-1 cluster, the same region linked to similar breakdowns in 2020 and 2021. Despite repeated failures in this location, the company has yet to explain why the data centre is still a recurring weak point.

Global Impact: From Banks to Gaming Platforms

The outage exposed the scale of global dependence on AWS. Major banks, telecom firms, and government agencies across Europe and North America reported downtime. In Britain, Lloyds Bank, Bank of Scotland, Vodafone, BT, and even the UK tax and customs authority (HMRC) experienced service interruptions.

For consumers, the impact was immediate and across-the-board. Social platforms like Snapchat and Reddit went dark, while fintech platforms such as Venmo, Robinhood, and Coinbase froze transactions. 

Gaming networks, including Fortnite, Roblox, Clash Royale, and Clash of Clans, were also affected. Lyft users in the United States were unable to book rides, and airline check-in systems at LaGuardia Airport in New York temporarily failed.

Artificial intelligence startup Perplexity, cryptocurrency exchange Coinbase, and trading app Robinhood were among those confirming that AWS was at the root of their service disruptions. Even Signal, the encrypted messaging platform, was hit. “This outage once again highlights the dependency we have on relatively fragile infrastructures,” said Jake Moore, global cybersecurity advisor at European security firm ESET.

Experts Warn of Fragile Cloud Dependency

The scale of the outage has reignited talks about the world’s overreliance on a handful of cloud providers, Amazon, Microsoft Azure, and Google Cloud, which collectively power a vast portion of global digital infrastructure.

“This was the third major AWS outage in five years linked to the same region,” said Ken Birman, professor of Computer Science at Cornell University. “When people cut costs and cut corners to try to get an application up, and then forget that they skipped that last step and didn’t really protect against an outage, those companies are the ones who really ought to be scrutinised later.”

Ryan Griffin, U.S. cyber practice leader at McGill and Partners, added that “for major businesses, hours of cloud downtime translate to millions in lost productivity and revenue.”

Recurring Weakness in US-EAST-1

The Ashburn-based US-EAST-1 cluster is AWS’s oldest and largest region, usually set as the default for many of its services. This makes it a single point of failure, and experts argue that the region’s recurring issues demonstrate the risks of centralised cloud design.

Nishanth Sastry, director of Research at the University of Surrey’s Department of Computer Science, said the incident was predictable. “The main reason for this issue is that all these big companies have relied on just one service,” he noted.

Market Reaction and Next Steps

Despite the global disruption, Wall Street remained largely indifferent. Amazon’s shares closed 1.6% higher at $216.48 on Monday. The company has promised to release a detailed post-event summary but has not clarified whether structural changes will be made to prevent a repeat of the incident.

The Amazon Web Services (AWS) global outage, the largest since last year’s CrowdStrike malfunction that crippled hospitals, banks, and airports, tells us that the cloud’s convenience comes with fragility.