AWS outage: what yesterday's event tells us about cloud dependency

Oct 22

On October 20 2025, a seismic event rippled quietly through the digital world: the services of AWS (Amazon Web Services) experienced a major outage, and with it, a wake-up call exploded across industries. While many companies rely on cloud infrastructures as foundational to their operations, this incident exposed how fragile those foundations may be.

What happened?

The disruption began in AWS’s US-EAST-1 region (northern Virginia), where a malfunction in a network load-balancer health monitor within EC2 internals triggered cascading failures.

Key symptoms included:

DNS resolution failures for AWS’s own services (notably the DynamoDB API endpoint) — meaning that even when compute capacity existed, many systems couldn’t “find” the services they needed.
Numerous high-profile downstream systems went offline or degraded: games (e.g., Fortnite, Roblox), streaming services, financial apps, messaging platforms.
The disruption lasted for many hours; while AWS confirmed “services returned to normal operations” by the afternoon in US Eastern time, backlog processing and lingering effects persisted.

What this event reveals about cloud dependency

The outage isn’t just a technical blip—it’s a mirror held up to current infrastructure models. For IT leaders, three inter-locking themes emerge:

1. Concentration risk is real, and it scales

Even though cloud providers advertise “99.99 % uptime,” when one large region or one major provider falters, the impact ripples wide. Analysts note that with only a handful of hyperscale providers (AWS, Microsoft Azure, Google Cloud) controlling a large share of cloud infrastructure, the adversity of a single failure grows.

This means: your organisation might think it’s “distributed” by using one major cloud provider across regions—but if those regions share control-plane dependencies, you still may be vulnerable. The fallacy of “outsourcing risk” to a provider simply shifts where your risk lives—it doesn’t eliminate it.

2. Architecture assumptions matter more than vendor assurances

You may trust your cloud vendor’s SLA, but the SLA only covers limited failure modes; it rarely covers your business outcomes (lost revenue, reputational harm, regulatory exposure). The outage underscores that being “in the cloud” is not the same as being resilient.

Lessons here:

Review which cloud regions and availability zones you depend on. Are critical services tied to the same region or to the same shared dependencies (e.g., DNS, identity, network load-balancers)?
Design for failure: introduce chaos, simulate loss of region, simulate network latency or control-plane failure. Recognise that large-scale cloud services are subject to the same risks as on-premises—but with more intensity because of scale and shared tenancy.
Evaluate your disaster-recovery posture not only for “infrastructure down” but for “service-dependency down” (e.g., downstream APIs, third-party dependencies, data-store endpoints). That’s where many failures hide.

3. Resilience is as much organisational as it is technical

The outage shows that while infrastructure failure is external, the response to it is internal. How you communicate, how you escalate, how you pivot, and how you recover matter. Decisions made under pressure define the real cost of the downtime.

Ensure incident-response plans span beyond “our data-center is down” to “the third-party demand-routing and API ecosystem we rely on is down.”
Post-incident, run a rigorous root-cause analysis and feed findings into governance, architecture and vendor-management. Public-cloud providers will release post-mortems—but you must interpret and internalise them for your stack.
Consider business-impact modelling: quantify minutes of service loss across key systems. When you can show to the leadership team or board the dollar cost per hour of cloud failure, then resilience becomes strategic, not only operational.

Strategic take-aways for IT leaders

Adopt a multi-region (and ideally multi-cloud) strategy for business-critical workloads, not just test/dev. Avoid placing all eggs in a single region or provider unless you’ve architected around the provider’s single-region risk.
Decouple dependencies: Ensure you’re not only using multiple zones/regions but also multiple dependencies (e.g., independent DNS, alternate identity/auth, alternate data-stores or backup pipelines).
Shift the conversation: Move from “cloud service provider promises high availability” to “we accept responsibility for our architecture and business continuity.” The provider is a partner—they’re not a guarantee.
Embed resilience metrics in operational dashboards: track not just system-uptime, but how downstream systems (APIs, partner services) respond to upstream failure. Build visibility.
Rehearse failure scenarios regularly: the next failure won’t look like the last one. (In this outage it was load-balancer health monitoring, not power or network alone.) So test variety.

Closing thoughts

Yesterday’s event is more than a headline; it’s a mirror for the industry. We live in a world where the digital backend is a shared space—vast, interconnected and efficient. But efficiency often comes with fragility. What yesterday taught us is that cloud dependency isn’t about vendor choice—it’s about architectural responsibility, systemic transparency, and organisational readiness.

As IT leaders, the question we must ask isn’t “Is the cloud safe?” but “Are we resilient?” Because the cloud will keep evolving—and so will the failure-modes. The better your architecture, the clearer your communication, and the more engaged your leadership, the more you’ll turn moments of crisis into moments of clarity.