Networking, Content Delivery, and Cost
This domain combines VPC networking and content delivery with cost and performance optimization, all core to day-to-day SysOps. Focus on connectivity, DNS, caching, and controlling spend.
VPC connectivity
A VPC uses subnets, route tables, internet gateways, and NAT gateways to control traffic. Public subnets route to an internet gateway; private subnets reach the internet outbound through a NAT gateway. VPC peering and AWS Transit Gateway connect networks, and VPC endpoints reach AWS services privately without traversing the internet.
DNS and load balancing
Amazon Route 53 provides DNS with routing policies such as latency, weighted, failover, and geolocation, plus health checks for failover. Elastic Load Balancing spreads traffic across targets: the Application Load Balancer routes HTTP by path and host, while the Network Load Balancer handles high-throughput TCP/UDP.
Content delivery and caching
Amazon CloudFront caches content at edge locations close to users, lowering latency and origin load, and integrates with WAF and TLS. Caching strategies and appropriate time-to-live values balance freshness against performance. Use CloudFront for static and dynamic content acceleration.
Cost and performance optimization
Right-size instances, use Auto Scaling to match demand, and choose purchase options: Savings Plans or Reserved Instances for steady workloads and Spot for interruption-tolerant work. AWS Cost Explorer and Budgets track and alert on spend, and S3 lifecycle policies move data to cheaper storage classes.