Design Cost-Optimized Architectures
Cost optimization delivers business value at the lowest price by matching resources to need and using the right pricing models. This chapter covers purchasing options, storage tiering, data transfer economics, and eliminating waste.
EC2 Purchasing Models
Choosing the right pricing model can dramatically cut compute cost. On-Demand suits short-term or unpredictable workloads, Reserved Instances and Savings Plans reward steady baseline usage with large discounts, and Spot Instances offer the deepest savings for interruption-tolerant work. Compute Savings Plans provide flexibility across instance families, Regions, Fargate, and Lambda. Match each workload's pattern to the model that minimizes cost.
Storage Cost Optimization
S3 storage classes let you pay according to access frequency. Standard suits hot data, Standard-IA and One Zone-IA reduce cost for infrequent access, and Glacier classes archive cold data at the lowest price with retrieval trade-offs. S3 Intelligent-Tiering automatically moves objects between tiers when access patterns are unknown or changing. Lifecycle policies transition and expire objects to control long-term cost.
Right-Sizing and Elasticity
Paying only for what you need avoids waste. Right-size instances and volumes using CloudWatch metrics and Compute Optimizer recommendations, and use Auto Scaling to release capacity when demand falls. Serverless services charge only for actual usage, eliminating idle cost. Continuously review utilization to shed overprovisioned resources.
Data Transfer and Migration Costs
Data movement can be a hidden expense, so design to minimize it. Keeping traffic within a Region and using CloudFront can reduce egress charges, while for large one-time migrations the AWS Snow Family ships data physically instead of saturating network links. Placing resources close to their consumers reduces cross-AZ and cross-Region transfer. Evaluate transfer patterns early in the design.
Managed Services and Monitoring
Managed and serverless services often lower total cost by removing operational overhead. Aurora Serverless, Fargate, and Lambda scale to demand so you avoid paying for idle infrastructure. Use AWS Budgets, Cost Explorer, and cost allocation tags to track spend and detect anomalies. Governance and visibility keep costs aligned with business value over time.