Post-Migration Operational Best Practices & AWS Config Policies


Post-Migration Operational Best Practices & AWS Config Policies

Once workloads have been migrated to AWS, the focus shifts from migration execution to **ongoing operations**, **governance**, and **continuous improvement**. The goal is to ensure that your new AWS environment remains secure, cost-optimized, resilient, and compliant over time. Below are key operational best practices and AWS Config policies to consider implementing after migration.

🏗️ 1. Operational Excellence & Governance

1.1 Establish a Cloud Operating Model

  • Define roles and responsibilities for Cloud Center of Excellence (CCoE), operations, security, and application teams.
  • Use AWS Organizations and Organizational Units (OUs) to enforce separation between production, non-production, and sandbox accounts.
  • Adopt Infrastructure as Code (IaC) using CloudFormation or Terraform to ensure consistent deployments.
Outcome: A structured operational model that supports scalability and repeatability across teams.

1.2 Centralized Logging & Monitoring

  • Enable AWS CloudTrail in all accounts, aggregating logs to a centralized S3 bucket for auditing.
  • Use Amazon CloudWatch for metrics and alarms, and CloudWatch Logs Insights for centralized log analysis.
  • Set up AWS Security Hub and GuardDuty for threat detection and compliance visibility.
  • Consider using OpenSearch or third-party SIEM tools for advanced log analytics.
Outcome: Unified visibility into operational health, security, and compliance across the cloud environment.

1.3 Backup, DR, and Resilience

  • Use AWS Backup to define centralized backup policies across services (EC2, RDS, EFS, DynamoDB).
  • Set Recovery Point Objective (RPO) and Recovery Time Objective (RTO) targets per workload and align with business SLAs.
  • Leverage multi-AZ and multi-region architectures for critical workloads.
Outcome: Reliable backup and disaster recovery posture aligned with business continuity requirements.

1.4 Cost Management and Optimization

  • Enable AWS Cost Explorer and Budgets to track usage and set budget alerts.
  • Use Trusted Advisor and Compute Optimizer to identify underutilized resources.
  • Tag resources consistently to allocate costs by team, project, or environment.
  • Consider Reserved Instances or Savings Plans for steady workloads.
Outcome: Ongoing visibility and control over operational costs.

1.5 Security and Identity Management

  • Enforce least privilege using IAM policies and roles; avoid using root accounts.
  • Integrate with an identity provider (e.g., AWS SSO or SAML) for centralized access control.
  • Enable MFA for all privileged users.
  • Regularly rotate credentials and access keys.
Outcome: A strong security baseline for identity, access, and privileged operations.

🛡️ 2. AWS Config Policies and Rules

AWS Config provides a powerful mechanism to track configuration changes, evaluate compliance against predefined or custom rules, and trigger remediation. Below are some key AWS Config policies you can enable post-migration:

Policy / Rule Description Purpose
required-tags Checks whether all resources have the required set of tags (e.g., CostCenter, Environment, Owner). Ensures proper cost allocation, ownership tracking, and lifecycle management.
restricted-ssh Ensures that no security groups allow unrestricted ingress on port 22 (0.0.0.0/0). Improves network security posture by enforcing restricted SSH access.
s3-bucket-server-side-encryption-enabled Checks whether your S3 buckets have server-side encryption enabled. Ensures data at rest is always encrypted.
rds-storage-encrypted Verifies that Amazon RDS database instances have storage encryption enabled. Enforces encryption compliance for databases.
ec2-instance-no-public-ip Ensures that EC2 instances are not assigned public IP addresses unless explicitly required. Reduces external attack surface and supports private networking architectures.
cloudtrail-enabled Checks whether CloudTrail is enabled in your account. Ensures continuous audit logging for governance and security.
iam-password-policy Validates that your IAM password policy requires complexity and rotation. Improves account security for console users.
eip-attached Checks whether Elastic IPs are associated with resources. Helps manage orphaned resources and control costs.
guardduty-enabled-centralized Ensures GuardDuty is enabled in all accounts and centralized in the security account. Supports centralized threat detection and monitoring.
root-account-mfa-enabled Checks whether the root account has MFA enabled. Protects the most privileged account in the AWS environment.
Tip: Combine AWS Config rules with AWS Systems Manager Automation or Lambda functions to enable automatic remediation (e.g., auto-encrypt S3 buckets that are found to be non-compliant).

🔁 3. Continuous Improvement

  • Adopt the AWS Well-Architected Framework for regular reviews of workloads across the five pillars: Operational Excellence, Security, Reliability, Performance Efficiency, and Cost Optimization.
  • Schedule periodic compliance audits using AWS Config Conformance Packs and Security Hub.
  • Automate patch management using Systems Manager Patch Manager.
  • Continuously refactor or modernize workloads over time (e.g., move from rehosted EC2 to managed containers or serverless).
Outcome: A continuously improving cloud environment that remains secure, efficient, and aligned with business goals.