Your question is DDoS Defense for Global CDN. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
Design a system to detect and mitigate DDoS attacks for a global content delivery network at Meta.
Explain the architecture, detection signals, mitigation controls, traffic-steering decisions, and operational response. Address volumetric, protocol, DNS, TLS, and application-layer attacks while minimizing collateral blocking of legitimate users.