What is AWS Cost Management and billing in depth?

Advanced AWS cost management for optimizing cloud spend: AWS Cost Explorer: analyze historical costs (up to 12 months) and forecast (3 months). Filter by service, region, tag, linked account. Rightsizing recommendations. RI/Savings Plans coverage and utilization reports. AWS Budgets: set custom cost/usage/RI/Savings Plan budgets. Alert when actual or forecasted spend exceeds threshold. Actions: notify via email/SNS, or automated action (restrict IAM, run SSM document, apply SCP). Cost Anomaly Detection: ML-based service that monitors spend patterns and alerts on unexpected increases. Per service, per tag, per linked account. Root cause analysis. Cost Allocation Tags: tag resources with cost center, project, team → Cost Explorer groups spending by tag. Enable cost allocation tags in Billing console to appear in Cost Explorer. Savings Plans vs RIs: Compute Savings Plans — flexible (any instance family, size, region, OS) up to 66% savings; EC2 Instance Savings Plans — specific instance family + region, up to 72% savings; RIs — specific instance type + region + OS, up to 75% savings (least flexible). Spot Instance management: Spot Requests → Spot Fleet → EC2 Auto Scaling with Spot. Spot Advisor shows interruption frequency per instance type. Spot + On-Demand blend: base on On-Demand, burst on Spot. Handle interruption: 2-minute warning via EventBridge → graceful shutdown, save state. AWS Compute Optimizer: ML-based rightsizing recommendations for EC2, EBS, Lambda, ECS on Fargate, Auto Scaling groups. Analyzes 14 days of CloudWatch metrics. S3 Storage Lens: organization-wide storage analytics — find unused buckets, incomplete multipart uploads, over-versioned buckets. S3 Intelligent-Tiering for automatic cost optimization.