Update regarding Vercel service disruption on October 20, 2025

Vercel experienced a significant service disruption due to an unexpected AWS us-east-1 outage, which affected its infrastructure and control plane operations, causing temporary disruptions in serving production traffic and impacting administrative functions like deployments and log processing. Despite Vercel's infrastructure being designed to withstand the loss of any of its 19 operational regions, a cascading failure led to a notable disruption in global caching services, peaking at a 22% failure rate in static file serving. Vercel managed to reroute traffic, restore services, and mitigate the cascading failure's root cause within hours, although some users faced continued issues related to AWS capacity constraints. Additionally, an outage of a feature flag provider, likely a downstream effect of the AWS disruption, further complicated the situation by affecting Vercel's control plane, leading to resource exhaustion and delaying certain administrative processes. Vercel's commitment to accountability is evident as they take full responsibility for the outage, and they plan to conduct a detailed postmortem to prevent future occurrences by rehearsing major regional disruptions and systematically addressing identified failure modes.