Platform Migration

Overview

This skill provides comprehensive guidance for migrating infrastructure platforms, cloud providers, container orchestration systems, CI/CD pipelines, and observability stacks. Focus is on infrastructure-level migrations that complement application modernization efforts.

Platform migrations are infrastructure-focused and should be paired with application migration strategies. Use cloud-neutral design patterns to reduce future migration effort, though multi-cloud strategies increase complexity while reducing vendor lock-in.

Core Migration Principles

Key Practices:

• Test everything in non-production first
• Automate using Infrastructure as Code (IaC)
• Migrate incrementally rather than "big bang"
• Maintain both platforms during stabilization
• Budget 20-30% more time than estimated
• Document architecture decisions and rationale

Avoid These Pitfalls:

• Migrating everything at once without phased approach
• Skipping non-production validation
• Ignoring cost estimation for target platform
• Failing to optimize during migration (pure lift-and-shift)
• Inadequate monitoring during transition
• Leaving resources running on both platforms post-migration

Migration Workflow

Step 1: Assessment and Planning

Identify Migration Type:

• Cloud-to-cloud (AWS↔GCP↔Azure)
• Kubernetes cluster migration (EKS→GKE→AKS)
• CI/CD platform change (Jenkins→GitLab→GitHub Actions)
• Monitoring stack migration (Prometheus→Datadog→New Relic)
• Container registry migration (Docker Hub→ECR→GCR→ACR)
• Network infrastructure transformation
• Infrastructure as Code migration (Terraform→CloudFormation→Bicep)

For detailed migration type workflows: See migration-types.md

Step 2: Inventory and Dependencies

• Document all resources in source platform
• Map dependencies between components
• Identify proprietary services without direct equivalents
• Estimate costs in target platform
• Assess technical constraints and requirements

Step 3: Design Target Architecture

• Map source services to target equivalents
• Design network topology and connectivity
• Plan IAM and security model
• Define migration approach (phased, parallel, cutover)
• Create rollback procedures

For IaC-specific migrations: See infrastructure-as-code-migration.md

Step 4: Risk Assessment and Mitigation

• Identify critical dependencies and single points of failure
• Plan for downtime windows
• Establish success criteria and validation tests
• Define rollback triggers and procedures

For comprehensive risk planning: See risk-management.md

Step 5: Pilot Migration

• Select non-critical workload for pilot
• Execute migration following documented procedure
• Validate functionality and performance
• Measure costs and resource utilization
• Document lessons learned and adjust plan

Step 6: Production Migration

• Migrate in planned waves/phases
• Implement data replication and synchronization
• Execute DNS cutover per service
• Monitor performance and errors continuously
• Validate each wave before proceeding

For validation procedures: See post-migration-validation.md

Step 7: Optimization and Cleanup

• Right-size resources based on actual usage
• Optimize costs using platform-native features
• Improve performance with platform capabilities
• Decommission source resources systematically
• Document final architecture

For cost optimization strategies: See cost-optimization-during-migration.md

Common Migration Scenarios

Cloud-to-Cloud Migration

Migrating between AWS, GCP, Azure, or moving from on-premise to cloud. Requires service mapping, network connectivity, and data transfer strategy.

Load: migration-types.md - Section 1: Cloud-to-Cloud Migration

Kubernetes Platform Migration

Moving clusters between EKS, GKE, AKS, or to self-managed Kubernetes. Involves workload migration, persistent storage, service meshes, and ingress controllers.

Load: migration-types.md - Section 2: Kubernetes Platform Migration

CI/CD Platform Changes

Transitioning between Jenkins, GitLab CI, GitHub Actions, CircleCI, or other platforms. Requires pipeline translation and secrets migration.

Load: migration-types.md - Section 3: CI/CD Platform Migration

Monitoring Stack Migration

Changing observability tools like Prometheus→Datadog, CloudWatch→New Relic. Includes metrics, logs, traces, and alerting.

Load: migration-types.md - Section 4: Monitoring Stack Migration

Container Registry Migration

Moving container images between Docker Hub, ECR, GCR, ACR, Harbor, or private registries.

Load: container-registry-migration.md

Network Infrastructure Migration

Transforming VPC configuration, VPN connections, DNS, load balancers, and CDN infrastructure.

Load: network-infrastructure-migration.md

Database Platform Migration

Migrating databases to different cloud providers or managed services.

Load: database-platform-migration.md

Migration Tools and Utilities

For platform-specific migration tools, automation scripts, and utilities:

Load: migration-tools.md

Includes cloud provider migration tools (AWS MGN, Azure Migrate, Google Cloud Migrate), Kubernetes tools (Velero, Kustomize), IaC tools (Terraformer, CDK), and data transfer utilities.

Reference Documentation

Migration Principles

Load: migration-principles.md
Complete best practices, anti-patterns, and key considerations for any platform migration.

Risk Management

Load: risk-management.md
Risk identification, mitigation strategies, contingency planning, and rollback procedures.

Post-Migration Validation

Load: post-migration-validation.md
Validation checklists, testing procedures, performance benchmarking, and cutover verification.

Cost Optimization

Load: cost-optimization-during-migration.md
Cost analysis, optimization strategies, and budget management during migration.

Output Formats

When generating migration artifacts, produce:

• Migration Plan: Detailed phases, timelines, dependencies, resources
• Architecture Diagrams: Source and target architecture with transition states
• Service Mapping: Complete mapping between source and target services
• Runbooks: Step-by-step execution procedures with rollback steps
• Validation Checklists: Acceptance criteria and testing procedures
• Risk Register: Identified risks, impact, probability, mitigation
• Cost Analysis: Comparative cost breakdown with optimization opportunities