On October 20, AWS us-east-1 experienced a major disruption, reminding us all that even the largest cloud providers can hit critical breaking points. This outage, rooted in DNS resolution failures, rippled through DynamoDB and core services, affecting platforms globally within minutes. For those designing resilient systems, several lessons stood out: • No Service Is an Island: Regional “isolation” can break down quickly when foundational services like DNS are shared across control and data planes. • Proactive Resilience Matters: Application-level DNS caching, circuit breakers, and graceful degradation are essential for surviving not just hardware blips, but full control-plane failures. • Multi-Region Is Non-Negotiable: True resilience comes from active-active/active-passive deployments, tested failovers, and diversified service discovery—even using multi-provider DNS when possible. • Test for Chaos: Borrow from chaos engineering—simulate DNS and endpoint failures before production faces them. This incident echoes past outages and serves as a wake-up call to revisit our architectural assumptions. As dependency chains grow deeper, the need for robust, fault-tolerant design grows ever more critical. Let’s build systems prepared to survive the next “impossible” event. #CloudReliability #AWSOutage #ResilienceEngineering #DevOps #SystemDesign #SaaS #CloudArchitecture #DNSEngineering #ChaosEngineering #SiteReliability #IncidentResponse #TechLeadership
AWS us-east-1 outage highlights importance of resilience in cloud design
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US-EAST-1 Outage: What Really Happened and What We Can Learn AWS US-EAST-1 experienced a major outage that rippled across the internet, caused by a DNS resolution failure for DynamoDB API endpoints. The impact was widespread: IAM (authentication) failed globally, locking engineers out of consoles and APIs. Core services like EC2, Lambda, CloudWatch, and Route 53 degraded or failed. Even after DNS was restored, retry storms and state sync issues extended the downtime. AWS’s response: Fixed the DNS issue within hours. Phased recovery and throttled high-impact services to stabilize the system. Cleared backlogged requests carefully to avoid overwhelming systems. Key lessons: DNS failures can cascade into global service outages. Single-region dependencies for critical services are risky. Control plane lockouts are a critical failure mode. Uncontrolled retries can worsen outages; throttling helps recovery. Plan for graceful degradation and regularly test failure scenarios. Sharing these lessons helps everyone build more resilient systems. #AWS #cloud #architecture #devops #infrastructure #engineering #outage
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🚨 Another AWS Outage - What Does This Mean for High Availability? Today, AWS is experiencing disruptions due to an issue in their internal subsystem. As millions of businesses rely on AWS for their infrastructure, even a partial outage can have cascading impacts. 🔗 [Live AWS Health Dashboard Updates](https://lnkd.in/gkvuurHx) This brings us back to a critical engineering question: 👉 Why are High Availability (HA) systems so hard to build? Even with world-class infrastructure like AWS, ensuring 100% uptime is an incredibly complex challenge. Here's why: 🔹 Dependencies - Most systems are built on a stack of services. A failure in one (like IAM, DNS, or networking) can ripple across your entire application. 🔹 Distributed Complexity - HA isn't just replication; it's about handling network partitions, failovers, state consistency, and more - all at scale. 🔹 False Assumptions - Assuming cloud services are "always up" leads to architectural blind spots. 🔹 Cost vs. Resilience - High availability comes with trade-offs: financial, operational, and architectural. So how do you protect your systems? ✅ Design for failure - Assume every component will fail. ✅ Multi-region or multi-cloud strategies - Not cheap, but often necessary for critical systems. ✅ Graceful degradation - Can your system still provide core value even in partial failure? ✅ Chaos engineering -Proactively test your system’s resilience under real failure scenarios. High availability isn't a checkbox. It's a mindset, a discipline, and a long-term investment. What strategies have you implemented to stay resilient during outages like this? #AWS #CloudComputing #DevOps #DistributedSystems #HighAvailability #ResilienceEngineering #Outage #SystemsDesign #ReliabilityEngineering
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✔️ Today's AWS outage is a stark reminder of a fundamental architectural truth: redundancy is not the same as resilience. Some of the affected companies had multi-region and multi-AZ strategies. So why did they still go down? As cloud engineers are discussing, the issue often traces back to dependencies on global control plane services like IAM, which have critical infrastructure in 'us-east-1'. Even if your application servers are spread across the globe, if control plane APIs are unavailable, deployments and certain operations can fail. 🛑 This isn't about blaming AWS—they've built remarkably resilient systems. This is about examining our own architectural assumptions: Are we building for infrastructure failure, or are we preparing for systemic failure? 💪 True resilience means architecting for scenarios where even foundational cloud services can be temporarily unavailable. This involves balancing risk and cost while considering: > Graceful Degradation: Can your system operate in a limited capacity if control plane services are unreachable? (Credential caching and local fallbacks help here) > Control Plane Independence: How long can your application run without making calls to management APIs? > Cross-Provider Failovers: For mission-critical services, do you have failover options that don't depend on the same provider's infrastructure? 🔑 The reality is that perfect resilience against all systemic failures isn't economically viable for every workload. The key is understanding your acceptable risk threshold and designing accordingly. ❔ What strategies has your team found effective for mitigating these global dependencies—and where have you chosen to accept risk? #AWSOutage #CloudArchitecture #HighAvailability #Resilience #SiteReliability
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AWS Outage: A Wake-Up Call for Multi-Cloud Resilience After reading several analyst breakdowns and technical post-mortems on the AWS outage (Oct 20, 2025), I wanted to share a quick summary and key lessons. The outage originated in US-EAST-1 (N. Virginia) and was caused by a DNS automation failure affecting Amazon DynamoDB. A subsystem that manages DNS health checks malfunctioned, returning empty records for the endpoint: `https://lnkd.in/gvmqfGZN` Since many AWS internal services (EC2, autoscaling, and control planes) rely on DynamoDB, this single DNS issue cascaded across multiple AWS systems — causing provisioning failures and widespread downtime. 💡 Key Takeaways ✅ Avoid single-region dependencies. Even “isolated” regions share hidden control-plane links. ✅ Design for control-plane failure. Workload redundancy alone isn’t enough — automation, DNS, and metadata systems need failover, too. ✅ Think multi-region or multi-cloud. Combining AWS + Azure (or other clouds) with proper failover and DNS routing boosts true resilience. 🌍 My Reflection This incident shows that even the most reliable clouds can fail — and architecture, not the provider, defines uptime. Multi-cloud isn’t just for redundancy; it’s becoming essential for business continuity and resilience. #AWS #Azure #MultiCloud #CloudComputing #DevOps #ResilienceEngineering #CloudArchitecture #EKS #AKS #Terraform
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First AWS. Then Azure. Two hyperscale failures. Ten days apart. Different root causes: DNS race in us-east-1, misconfigured Azure Front Door push, but the same boardroom question: "Where exactly does your architecture fail under pressure?" Resilience is not uptime. It’s design discipline. We no longer speak of "multi-cloud immunity." That term belongs to fiction. What we’re managing is blast radius, and that begins with executive control over three non-negotiables: Edge Independence 🌐 DNS and traffic control must operate outside your cloud estate. Internal routing loops during outages create perfect storm scenarios. If your escape hatch is in the same building that’s burning, it’s not an escape. Tiered Resilience 🛡️ Not every service warrants five-nines. Classify by financial and operational criticality: • Tier 0: Fail-static survivability. • Tier 1: Warm standby. • Tier 2: Contingency, not continuity. Cellular Runtime 🧬 Architect for failure isolation. AWS's DNS incident became a cascading storm because retry logic was monolithic. Your systems need compartments that fall alone, not dominoes. What to do now: Reclassify digital services into Tier-0/1/2 by revenue and risk impact. Transition DNS to an independent, fault-tolerant provider. Harden edge configuration with canary deploys, segmented domains, and rollback strategies. Run game-day simulations specifically targeting cloud-edge and DNS control plane failures. Your cloud platform will fail. That’s a certainty. The only variable is how much damage it does to you. #BoardResilience #CloudArchitecture #RiskManagement #CISO #DevOps #DigitalContinuity #SaaSStrategy
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Lessons Learned from the AWS DNS Failure When AWS sneezes, the internet catches a cold. During a recent AWS DNS outage, parts of the cloud ecosystem went dark affecting load balancers, APIs, and authentication systems across multiple regions. As engineers, moments like this remind us that even the most resilient infrastructure can fail and that resilience is built not by avoiding failure, but by learning from it. Here are my top lessons learned: 1. Redundancy IS NOT Resilience Even highly redundant systems can fail if dependencies (like DNS) are centralized. Lesson: Build multi-provider or multi-region DNS strategies and avoid a single point of name resolution which leads to single point of failure. 2. Visibility Saves Recovery Time Teams with proactive monitoring (Route53 health checks, CloudWatch metrics, and synthetic tests) spotted impact faster. Lesson: Invest in observability metrics, logs, and traces should narrate your system's story in real time. 3. Graceful Degradation Matters Apps that degraded gracefully (serving cached data or limited functionality) kept users calm. Lesson: Always design fallback mechanisms even a partial service is better than a full outage. 4. Incident Communication Is Half the Battle The best teams communicated early, shared context, and guided stakeholders clearly. Lesson: Build and test incident communication playbooks silence is never golden in outages. 5. Postmortems Are Gold Mines AWS’s openness in publishing their post-incident analysis helps the whole industry. Lesson: Do blameless postmortems by focusing on process improvement, not finger pointing. Failures like this remind us: “Resilience is not built during the outage, it is engineered long before it.” #AWS #DNSError #CloudComputing #SystemEngineering #DevOps #IncidentResponse #ResilienceEngineering #InfrastructureAsCode #SiteReliabilityEngineering #Automation #Monitoring #PostmortemCulture #LearningFromFailure #Observability #EngineeringLeadership
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The AWS Outage Just Taught Us a $6.5M Lesson in Resilience Yesterday's 15-hour AWS outage wasn't just downtime—it was a masterclass in what happens when blast radius meets poor architecture. Over 1,000 companies. 150+ apps down. 6.5 million frustrated users. The culprit? A single DNS failure in US-EAST-1 affecting the DynamoDB control plane. Here's what every cloud architect should be discussing today: 🔴 Single Point of Failure & Control Plane Dependency When your entire infrastructure relies on one region's control plane for IAM and global services, you're one DNS resolution away from chaos. 🌐 Cross-Regional Failover Strategy Implement active-active or active-passive failover across regions. Your RTO (Recovery Time Objective) shouldn't be measured in hours. ☁️ Multi-Cloud Architecture True resilience means avoiding vendor lock-in. Distribute critical workloads across AWS, Azure, and GCP with geo-redundant deployments. ⚡ Circuit Breaker Pattern Services should fail fast when dependencies are unhealthy. Implement circuit breakers to prevent cascading failures and give systems time to recover. ⚡ Multi-Workload Distribution Critical services need geographic and provider diversity. Your payment gateway shouldn't share the same fate as your analytics dashboard. 🧪 Chaos Engineering Are you testing failure scenarios? Run chaos experiments to validate your resilience patterns before production does it for you. 📊 Define Your RPO & RTO RPO (Recovery Point Objective): How much data can you afford to lose? RTO: How quickly must you recover? Know these numbers for every critical service. 💡 The Real Cost Beyond immediate revenue loss: customer trust erosion, SLA breaches, and reputation damage that lasts far longer than 15 hours. The question isn't IF another major outage will happen—it's WHEN. Are your systems designed to survive it? **#CloudArchitecture #AWS #DevOps #MultiCloud #DisasterRecovery #ChaosEngineering #SRE #CloudEngeering #Resilience
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🌩️ AWS Outage & The Single-Region Trap 🌩️ Today’s AWS outage — centered in the US-EAST-1 region — reminded the entire cloud community of one core principle: resilience cannot exist within a single region. When a region like US-EAST-1 experiences internal subsystem failures (in this case, DNS and load-balancer health monitoring), services that rely exclusively on that region lose routing stability and data access. Even global apps crumble, not because of code issues, but because their control planes and data paths share a single geographic dependency. The technical chain reaction is fascinating: 1️⃣ DNS resolution fails → traffic routing breaks. 2️⃣ Load balancers can’t confirm healthy targets → requests drop or loop. 3️⃣ Dependent services (EC2, DynamoDB, S3, API Gateway) start timing out → apps globally go dark. This event reinforces that multi-region design is not a luxury — it’s a survival strategy. Architects should: Deploy workloads across multiple regions (active-active or active-passive). Replicate data asynchronously for regional independence. Decouple monitoring, DNS, and identity systems from a single regional control plane. Resilience is built through distribution, redundancy, and deliberate chaos testing — because in cloud computing, every “single region” is a potential single point of failure. #AWS #CloudArchitecture #Resilience #DevOps #SiteReliability #InfrastructureEngineering
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Today’s AWS disruption was more than just downtime. it was a reminder of how deeply connected and vulnerable modern systems truly are. A small DNS glitch triggered a DynamoDB ripple, and the result was global impact across industries. Distributed systems don’t fail silently, they fail loudly and together, exposing every hidden dependency along the way. When a single failure can pause half the internet, it stops being an outage and becomes a lesson. True resilience isn’t built during uptime,it’s engineered through preparation for failure. Multi-cloud strategies, regional failovers, disaster recovery planning, and chaos testing are no longer optional they are survival strategies in a cloud-dependent world. #AWS #CloudOutage #SystemDesign #DistributedSystems #ResilienceEngineering #DevOps #CloudArchitecture
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⚙️ When a Single DNS Record Shook the Cloud On October 20 2025, a major AWS outage in the US-EAST-1 region disrupted hundreds of applications globally. Root cause? 👉 A bug in AWS’s internal DNS automation for DynamoDB created an empty DNS record. That one error propagated through internal resolvers and broke endpoint resolution across multiple AWS services. What followed was a perfect storm: Failed service discovery API and control-plane timeouts Retry storms increasing load Cascading failure across managed services When DNS fails, nothing works — even recovery. 🧠 Technical Chain Reaction 1️⃣ Faulty DNS update → empty A-record created. 2️⃣ Propagation → poisoned caches, partial lookups. 3️⃣ Dependency loss → internal services using DynamoDB couldn’t locate endpoints. 4️⃣ Retry storms → amplified traffic on degraded systems. 5️⃣ Control-plane impact → provisioning & scaling operations failed globally. A single misconfigured record triggered a systemic failure — proof that reliability = controlling blast radius, not just uptime. 🔍 Core Engineering Lessons ✅ Isolate automation pipelines. DNS/config changes must be staged region-by-region with rollback triggers. ✅ Design for failure. Multi-zone & multi-region redundancy is non-negotiable for DNS, IAM, and config stores. ✅ Independent control planes. Don’t let your recovery system depend on the same DNS or DB as production. ✅ Multi-provider DNS. Route53 + Cloudflare, or hybrid authoritative setups, reduce single-point dependency. ✅ Test chaos. Simulate DNS blackouts and discovery delays — don’t stop at VM or node failures. 🧩 Key Takeaway One empty DNS record took down parts of the internet. Reliability isn’t about 99.999% uptime — it’s about surviving the 0.001%. Design for failure. Test for chaos. Prepare for the unexpected. Because in cloud engineering, resilience is the real SLA. #AWS #Cloud #SRE #DevOps #DNS #Outage #Infrastructure #Resilience #ReliabilityEngineering #Postmortem
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Performance Engineer
3wThis incident is a reminder that resilience isn’t just about redundancy, it’s about preparedness. Even the most reliable cloud platforms can falter, but how our systems respond in those moments defines reliability.