On November 18, 2025, a major outage at Cloudflare, a key player in internet infrastructure, disrupted services globally, affecting platforms like X (formerly Twitter) and ChatGPT by causing 5xx errors and service interruptions. The outage was due to a configuration mismatch during a software rollout rather than a cyberattack, highlighting the significant risks and financial impacts of relying on third-party services. It underscored the importance of resilience testing and proactive architectural strategies to mitigate such risks, such as multi-provider redundancy, aggressive caching, robust monitoring, and graceful degradation. Harness, a company specializing in resilience solutions, advocates for regular resilience testing to identify vulnerabilities, suggesting that tools like their Chaos Engineering platform can help businesses simulate potential failures and improve their resilience posture. This incident served as a wake-up call for businesses to audit their dependencies and strengthen their systems to withstand future disruptions.