Han Highemerly

Networking

TCP/IP BGP OSPF MPLS L2VPN L3VPN Optical network IPv6 IPv6 transition technologies (DS-Lite, MAP-E) Network design

HTTP & DNS

HTTP HTTP/2 / HTTP/3 HTTPS (TLS) mTLS Authoritative DNS (BIND, Route 53, Zone transfer, etc.) OCSP ACME DNSSEC SMTP ActivityPub

Cloud & Middleware

Nginx Content Delivery / CDN (Cloudflare, AWS, etc.) Object Storage (S3, R2, etc.) Serverless (Lambda, Cloudflare Workers, CloudFront Functions) Docker Kubernetes PostgreSQL Elasticsearch

Observability & SRE & Performance

Prometheus VictoriaMetrics Grafana Loki Fluent Bit SNMP Web performance (Core Web Vitals, etc.) RUM (Real User Monitoring) SLO Design

CI/CD

GitHub Actions GitOps

Security

WAF Web security (CSP, etc.) DDoS mitigation Rate limiting Bot mitigation

Application

Ruby on Rails Next.js Python Go

Other

Project management English
Last updated August 2026 Contact