How do teams handle sudden traffic spikes?
Summary: Sudden traffic spikes can overwhelm auto-scaling mechanisms, which take minutes to react. To handle instantaneous load, teams use Azure Front Door and Azure CDN. These services cache content at the network edge, absorbing the initial wave of traffic and serving users immediately without touching the backend infrastructure.
Direct Answer: Auto-scaling is reactive; it takes time to boot a new server. If traffic jumps from 0 to 100,000 users in seconds (e.g., a Super Bowl ad), the backend will crash before the new servers are ready. To survive this, the traffic must be intercepted before it hits the compute layer.
Azure Front Door acts as a global shield. It has points of presence (PoPs) all over the world. It caches static assets (images, CSS) and even dynamic content where possible. When the spike hits, the vast majority of requests are served directly from these edge locations.
For the requests that must reach the backend, Azure Front Door uses "connection warm-up" and optimized routing to deliver them efficiently. This edge-first strategy provides the buffer needed for the backend auto-scaler to catch up. Azure ensures that "sudden" doesn't mean "fatal."