The 7 Cloud Migration Strategies

[srisivakumar]

Cloud Migration Strategies

Strategy	Definition	Purpose	Pros	Cons	Cost Optimization Techniques	Cloud-Native Tool Recommendations	Industry Regulations	Real-World Use Case
Rehost (Lift and Shift)	Moving applications as-is from on-prem to the cloud without modification.	Fast migration with minimal changes.	🚀 Quickest migration 💰 Low upfront cost 📉 Minimal training needed	🔧 No cloud-native benefits 💸 Higher long-term cost	💲 Optimize with: 🛑 Sustained Use Discounts 🌍 Use Preemptible VMs for batch jobs 📉 Rightsize Compute Engine instances	Compute Engine, Migrate for Compute Engine, Cloud VPN	PCI DSS, ISO 27001	A bank migrates on-prem payment processing VMs to Compute Engine and applies Committed Use Discounts (CUDs) to save 40%.
Replatform (Lift, Tinker, and Shift)	Moving applications with minor optimizations (e.g., shifting databases to managed services).	Improves performance, security, and scalability.	⏫ Better efficiency than Rehost 💲 Some cost savings over time 🔧 Fewer operational overheads	⏳ Takes longer than Rehost 📉 Still not fully cloud-native	💲 Optimize with: 🔄 Move to Managed Databases (Cloud SQL, Spanner) 🔑 Use Auto-scaling for workloads 💾 Tiered Storage with Lifecycle Policies	Cloud SQL, GKE, Cloud Run, Cloud Storage	SOC 2, HIPAA	A health insurer moves claims DB to Cloud SQL and enables automatic backups with lifecycle policies, cutting storage costs by 30%.
Refactor (Re-architect)	Rewriting application components to leverage cloud-native architectures.	Maximizes scalability, resilience, and cost-efficiency.	📈 Highest long-term efficiency ⚡ Improved performance & security 🌍 Enables global scalability	💰 High upfront investment ⏳ Longest migration time	💲 Optimize with: 🔀 Move to Serverless (Cloud Functions, Cloud Run) ⚡ Use Cloud Spanner for auto-scaled DB costs 🌐 Adopt Microservices with API Gateway	GKE, Anthos, Cloud Functions, Pub/Sub, Firestore	GDPR, CCPA	A fintech rebuilds trading services in GKE with Pub/Sub, reducing compute costs by 50% with event-driven architecture.
Repurchase (Drop and Shop)	Replacing an existing application with a SaaS solution instead of migrating it.	Reduces maintenance and eliminates licensing costs.	💸 No maintenance required ⚡ Faster implementation 📉 Eliminates tech debt	🔐 Vendor lock-in risks 🛠️ Limited customization	💲 Optimize with: 📊 Evaluate SaaS Pricing Tiers 🔍 Negotiate Enterprise License Agreements 🌍 Leverage SaaS with Pay-as-you-go Models	Salesforce (CRM), Workday (HR), SAP on GCP	SOC 2 Type 2, ISO 27001	A firm switches from on-prem ERP to SAP on GCP, reducing IT maintenance costs by 60%.
Retire (Decommission Unused Assets)	Shutting down outdated or redundant applications.	Eliminates technical debt and optimizes infrastructure.	💰 Significant cost savings 📉 Reduces attack surface 🚀 Increases cloud efficiency	❌ Requires careful dependency analysis	💲 Optimize with: 📂 Archive data to Coldline/Nearline Storage 🛠️ Shut down idle VM instances & disks 📑 Use BigQuery for cost-efficient analytics	BigQuery, Cloud Storage (cold storage)	PCI DSS, GDPR	A global bank decommissions legacy transaction logs, archiving them to Coldline Storage, saving 80% in storage costs.
Retain (Keep On-Prem for Compliance/Latency Needs)	Keeping workloads on-prem due to regulatory or performance constraints.	Supports hybrid cloud needs.	🔐 Maintains regulatory compliance ⚡ Low-latency for sensitive workloads	🚀 Requires hybrid infrastructure expertise	💲 Optimize with: 🔄 Use Anthos for hybrid deployments 🔌 Optimize interconnect costs with Cloud Interconnect 📡 Implement Edge Computing for local processing	Anthos, Cloud Interconnect, VPC Service Controls	FINRA, GDPR, HIPAA	A stock exchange keeps trading on-prem but moves risk analytics to GCP, cutting on-prem compute costs by 40%.
Relocate (Move Between Cloud Regions or Providers)	Migrating workloads between cloud regions or from one provider to another.	Improves availability, compliance, and cost efficiency.	🌍 Multi-region availability 💰 Cost optimization 📉 No major re-architecture required	🔄 Potential downtime risks 📑 Licensing implications	💲 Optimize with: 🔁 Use Multi-Cloud Discounts (Anthos, Kubernetes Engine) 📶 Optimize egress costs with Private Google Access 🛠️ Move data with Transfer Appliance for large migrations	Anthos, Cloud DNS, Migrate for Compute Engine	ISO 27701, GDPR	A finance firm migrates from AWS to GCP, reducing TCO by 35% by using Anthos for multi-cloud governance.