Network protocols, TCP/IP stack, and building networked systems.
Every DNS record type for production: A, CNAME, MX, TXT, CAA, SRV. TTL failover math, SPF/DKIM/DMARC, GeoDNS, and DNSSEC.
How HTTP evolved from sequential text to multiplexed binary streams over QUIC. What each version solves and when to upgrade.
What head-of-line blocking costs, how QUIC solves it, and how to choose the right transport for real-time and API workloads.
Request lifecycle from DNS through TCP, TLS, CDN, and load balancing — with production latency debugging at every layer.
How Kubernetes networking actually works — CNI plugins, kube-proxy iptables chains, the CoreDNS tax, and the debugging commands that find real problems.