'Error' in Microsoft's DDoS defenses amplified 8-hour Azure outage

Microsoft reported a large DDoS attack that triggered a global Azure outage; although Microsoft's DDoS defenses activated, an implementation error amplified the impact and disrupted multiple services (Azure App Services, Application Insights, IoT Central, Log Search Alerts, Azure Policy, the Azure portal, and some Microsoft 365/Purview services) between ~11:45 and 20:48 UTC. Microsoft says the bulk of impact was mitigated by 14:10 UTC and will publish post-incident reviews (Preliminary PIR in ~72 hours, Final PIR in ~2 weeks).