Cost Optimization

Airbnb's AWS bill exceeded $110 million in 2021. At that scale a 20% reduction saves $22 million per year. Cloud cost optimization is not optional for product economics - it is the difference between a profitable SaaS and one that burns cash on infrastructure inefficiency.

• Capital One saved over $100M/year by moving from Reserved EC2 to Compute Savings Plans, which apply across EC2, Fargate, and Lambda automatically.
• Spotify saves ~60% on batch processing costs by using Spot (preemptible) instances with job checkpointing to handle interruptions gracefully.
• Slack reduced its AWS bill by 35% in one quarter by right-sizing instances using Compute Optimizer - over 70% ran below 20% average CPU.

Reserved Instances

**Reserved Instances** is a foundational pattern in Cost Optimization. It addresses specific operational, scalability, or cost challenges that cloud-native architectures face at scale.

Reserved Instances is a standard topic in AWS Solutions Architect and senior cloud engineering interviews. Understanding the trade-offs and failure modes is more valuable than memorizing the exact API.

Savings Plans

**Savings Plans** is a foundational pattern in Cost Optimization. It addresses specific operational, scalability, or cost challenges that cloud-native architectures face at scale.

Savings Plans is a standard topic in AWS Solutions Architect and senior cloud engineering interviews. Understanding the trade-offs and failure modes is more valuable than memorizing the exact API.

Spot Instances

**Spot Instances** is a foundational pattern in Cost Optimization. It addresses specific operational, scalability, or cost challenges that cloud-native architectures face at scale.

Spot Instances is a standard topic in AWS Solutions Architect and senior cloud engineering interviews. Understanding the trade-offs and failure modes is more valuable than memorizing the exact API.

Right-Sizing

**Right-Sizing** is a foundational pattern in Cost Optimization. It addresses specific operational, scalability, or cost challenges that cloud-native architectures face at scale.

Right-Sizing is a standard topic in AWS Solutions Architect and senior cloud engineering interviews. Understanding the trade-offs and failure modes is more valuable than memorizing the exact API.

Key Ideas

• **Reserved Instances:** 1 or 3 year commitment to specific instance type and region for up to 72% discount vs on-demand
• **Savings Plans:** flexible 1 or 3 year commitment to a compute spend rate ($/hour) that auto-applies across EC2, Fargate, and Lambda
• **Spot Instances:** spare AWS capacity at up to 90% discount; 2-minute interruption notice; right for stateless, fault-tolerant, or checkpointable workloads
• **Right-sizing:** matching instance size to actual workload; Compute Optimizer analyzes CloudWatch metrics and recommends downsizing

Related Topics

These topics form the broader Cost Optimization ecosystem:

• Multi-Account Strategy — Consolidated billing and organization-wide Savings Plans sharing are key multi-account cost levers
• Cloud Architecture Design — Cost efficiency is one of the five Well-Architected Framework pillars - baked into design, not bolted on
• Performance Tuning — Right-sizing improves cost and performance simultaneously - under-provisioned instances cause latency, over-provisioned waste money

Вопросы для размышления

• How does the architecture for Cost Optimization change when scaling from 1,000 to 10 million users?
• What are the primary failure modes in a Cost Optimization system, and what monitoring detects them before users are affected?
• What trade-offs would change the architectural decision for Cost Optimization in a regulated industry with strict data residency requirements?

Связанные уроки

• devops-25