21K req/sp99 102msHTTP/3→HTTP/2100% success under QUIC packet loss
›Built an HTTP/3 (QUIC) → HTTP/2 edge proxy with dual ingress (QUIC + HTTP/1.1/2 Alt-Svc upgrade) and hierarchical routing (O(1) exact match + radix trie fallback).
›Implemented multi-level overload protection with inflight limits, adaptive admission control, brownout shedding, circuit breakers, and retry/hedging logic.
›Hardened control plane with TLS APIs, constant-time token auth, privilege dropping (CAP_NET_BIND_SERVICE), and RFC-compliant header stripping.
›Added distributed quota policies (Redis or in-memory backed) for cluster-wide request budgets, plus a packaged observability bundle — Prometheus alerts, SLOs, and Grafana dashboards for traffic, admission, and backend health.
›Achieved 21K req/s (p99: 102ms) on 4-core test system; sustained 12.5K req/s under QUIC packet loss with 100% success rate.