A prioritized checklist of AWS best practices covering security, cost optimization, reliability, and operational excellence to help teams build robust, secure, and efficient cloud architectures.
1. Enable MFA on the root account and all IAM users
The root account has unrestricted access; enabling MFA adds a critical second layer of defense. Enforce MFA via IAM policies and use hardware tokens or authenticator apps for privileged accounts.
2. Apply the principle of least privilege to all IAM roles and policies
Grant only the permissions required for a specific task and nothing more. Use IAM Access Analyzer and AWS managed policies as a baseline, then scope down with condition keys.
3. Rotate and avoid long-lived access keys
Long-lived IAM access keys are a common breach vector; prefer IAM roles attached to EC2 instances, Lambda functions, and ECS tasks instead. If keys are required, rotate them every 90 days and audit usage with CloudTrail.
4. Enable AWS CloudTrail in all regions and ship logs to a dedicated S3 bucket
CloudTrail records API calls across your account, providing an audit trail for security investigations. Store logs in a separate, locked-down account or S3 bucket with Object Lock enabled to prevent tampering.
5. Use VPC security groups and NACLs to segment network traffic
Apply security groups at the resource level as stateful firewalls and NACLs at the subnet level as a stateless second layer. Restrict inbound rules to known CIDR ranges and avoid 0.0.0.0/0 on sensitive ports.
6. Enable AWS Config rules and Security Hub for continuous compliance
AWS Config evaluates resources against desired configuration rules in real time; Security Hub aggregates findings from Config, GuardDuty, Inspector, and Macie into a single compliance dashboard.
7. Right-size instances and use Savings Plans or Reserved Instances for predictable workloads
Use AWS Compute Optimizer recommendations to match instance families to actual CPU and memory usage. Commit to Savings Plans or Reserved Instances for steady-state workloads to achieve up to 72% cost reduction over On-Demand.
8. Tag all resources consistently with a mandatory tagging strategy
Define required tags such as Environment, Owner, CostCenter, and Project and enforce them via AWS Organizations Service Control Policies (SCPs) or Config rules. Consistent tagging enables accurate cost allocation, automation, and compliance reporting.
9. Architect for high availability across multiple Availability Zones
Deploy compute, database, and load-balancing tiers across at least two AZs to eliminate single points of failure. Use Auto Scaling groups with multi-AZ configurations and Multi-AZ RDS or Aurora clusters.
10. Encrypt data at rest and in transit using AWS KMS and TLS
Enable server-side encryption on S3 buckets, EBS volumes, RDS instances, and DynamoDB tables using AWS KMS customer-managed keys. Enforce HTTPS-only access via bucket policies and load-balancer listener rules.
11. Set up AWS Budgets and Cost Anomaly Detection alerts
Create monthly and forecasted budgets per account, service, and tag to catch unexpected spend early. Enable Cost Anomaly Detection to receive automatic alerts when spending deviates significantly from historical baselines.
12. Use Infrastructure as Code (IaC) with CloudFormation or Terraform for all provisioning
Define all AWS resources in version-controlled IaC templates to ensure repeatability, auditability, and consistent drift detection. Use cfn-lint or Terraform validate in CI/CD pipelines to catch errors before deployment.
13. Enable Amazon GuardDuty across all accounts and regions
GuardDuty uses machine learning and threat intelligence to detect anomalous API calls, cryptocurrency mining, and compromised credentials with near-zero operational overhead. Enable it organization-wide via AWS Organizations for centralized findings.
14. Implement automated backups and regularly test restore procedures
Use AWS Backup to centrally manage and schedule backups for RDS, EBS, DynamoDB, EFS, and FSx with defined retention policies. Run restore drills at least quarterly to validate recovery time objectives (RTOs) and recovery point objectives (RPOs).