Networking
BGP
OSPF
MPLS
L2VPN
L3VPN
Optical network
IPv6
IPv6 transition technologies (DS-Lite, MAP-E)
SNMP
Network design
HTTP & DNS
HTTP
HTTP/2 & 3
HTTPS (TLS)
mTLS
Authoritative DNS (Bind, Route53, Zone transfer, etc.)
OCSP
ACME
DNSSEC
SMTP
ActivityPub
Cloud & Middleware
Nginx
Contents Delivery (Cloudflare, AWS, etc.)
Object Storage (S3, R2, etc.)
Serverless - Lambda
Serverless - CloudFront Functions
Serverless - Cloudflare Workers
Docker
Kubernetes
PostgreSQL
Elasticsearch
Observability & SRE & Performance
Prometheus
VictoriaMetrics
Grafana
Loki
Fluent Bit
Web performance (Core Web Vitals)
RUM
SLO Design
CI/CD
GitHub Actions
GitOps
Application
Web security - OWASP Top 10
Web security - DDoS mitigation
Web security - CSP
Ruby on Rails
Next.js
Python
Go