The Netlify Application Delivery Network (ADN) was affected by a Distributed Denial of Service (DDoS) attack on November 4th, 2019, which resulted in disruption of service for some Pro and Starter customers. The Enterprise ADN network was not affected due to its different server topology, throughput, and internal configuration. The incident highlighted the importance of having resilient networks and efficient caching mechanisms to mitigate the impact of such attacks. Netlify has taken measures to improve its DDoS protection, including implementing a more efficient domain blocking system, reducing human intervention in dropping client connections, and improving its connection drop measures using eBPF and XDP. The company is also working on creating regional layers of cache servers and revising its provisioning processes to make the process of bringing capacity online more seamless and safe.