Cloud migration is the process of moving applications, data, and infrastructure from on-premise servers to cloud platforms like AWS, Azure, or Google Cloud. When done right, it reduces infrastructure costs by 25-40%, improves reliability, and enables rapid scaling. When done wrong, it causes data loss, unexpected costs, and weeks of downtime.
This 15-step checklist, based on our cloud migration experience at Aquarious Technology, ensures a smooth transition.
Pre-Migration (Steps 1-5)
Step 1: Inventory All Workloads
Document every application, database, service, and integration currently running. Include: technology stack, dependencies, data volume, user count, criticality level (Tier 1/2/3), and current hosting costs. You can't migrate what you haven't mapped.
Step 2: Classify Migration Strategy Per Workload
Not everything migrates the same way. Use the 6 R's framework:
| Strategy | Description | When to Use |
|---|---|---|
| Rehost (Lift & Shift) | Move as-is to cloud VMs | Quick migration, minimal changes |
| Re-platform | Minor optimization during move | Database migration to managed services |
| Refactor | Restructure for cloud-native | Apps that need scalability improvements |
| Re-architect | Complete redesign | Monolith to microservices transformation |
| Retire | Decommission | End-of-life applications |
| Retain | Keep on-premise | Regulatory or latency requirements |
Step 3: Choose Your Cloud Provider
| Criteria | AWS | Azure | GCP |
|---|---|---|---|
| Best for | Broadest services, startups | Microsoft ecosystem, enterprise | AI/ML, data analytics |
| Global presence | 33 regions | 60+ regions | 40 regions |
| Pricing | Pay-as-you-go, reserved | Pay-as-you-go, hybrid | Per-second billing |
| Managed databases | RDS, Aurora, DynamoDB | SQL Database, CosmosDB | Cloud SQL, BigTable |
Step 4: Establish Security & Compliance Framework
Before moving anything: define IAM policies, VPC architecture, encryption standards (AES-256 at rest, TLS 1.3 in transit), compliance requirements (HIPAA, PCI DSS, GDPR, DPDP Act), and incident response procedures.
Step 5: Calculate Total Cost of Ownership (TCO)
Use AWS Calculator, Azure Pricing Calculator, or GCP Pricing Calculator to estimate monthly costs. Include: compute, storage, data transfer, managed services, monitoring tools, and support plans. Add 20% buffer for the first 6 months while you optimize.
Migration Execution (Steps 6-10)
Step 6: Set Up Landing Zone
Create the cloud environment before migrating workloads: VPCs, subnets, security groups, IAM roles, logging (CloudTrail/Activity Log), and monitoring (CloudWatch/Azure Monitor).
Step 7: Migrate Data First
Data migration is the highest-risk phase. Use managed migration services (AWS DMS, Azure Database Migration Service, GCP Database Migration Service) for databases. For large datasets, use offline transfer (AWS Snowball, Azure Data Box) or incremental replication.
Step 8: Migrate Applications in Priority Order
Start with Tier 3 (non-critical) applications to build team confidence. Then Tier 2. Migrate Tier 1 (mission-critical) last, with extensive testing and rollback plans.
Step 9: Implement Zero-Downtime Cutover
For production applications: use blue-green deployments, database replication with switchover, DNS-based traffic shifting, and scheduled maintenance windows for final cutover. At Aquarious, we've achieved zero unplanned downtime on every migration.
Step 10: Validate Everything
Post-migration validation checklist:
All data integrity checks pass (row counts, checksums)- Application functionality tests pass
- Performance benchmarks match or exceed on-premise
- Security scans show no new vulnerabilities
- Monitoring and alerting is operational
- Backup and disaster recovery is tested
Post-Migration (Steps 11-15)
Step 11: Optimize Costs
Turn off over-provisioned instances, implement auto-scaling, use reserved instances for predictable workloads, and enable cost alerts. Most companies reduce cloud costs by 20-30% in the first 3 months of optimization.
Step 12: Set Up CI/CD Pipelines
If you haven't already, implement continuous integration and deployment using GitHub Actions, GitLab CI, or AWS CodePipeline. Automating deployments reduces human error and accelerates release cycles.
Step 13: Implement Comprehensive Monitoring
Set up application performance monitoring (Datadog, New Relic), infrastructure monitoring (CloudWatch, Grafana), log aggregation (ELK Stack, CloudWatch Logs), and uptime monitoring (PagerDuty, Opsgenie).
Step 14: Document Everything
Create runbooks for common operations, disaster recovery procedures, architecture diagrams, and cost optimization reports. This documentation is critical for team onboarding and incident response.
Step 15: Schedule Quarterly Cloud Reviews
Cloud costs and architecture should be reviewed quarterly: right-size instances, evaluate new managed services, update security policies, and ensure compliance with evolving regulations.
Common Cloud Migration Mistakes
| Mistake | Consequence | Prevention |
|---|---|---|
| Lifting everything without optimization | Higher cloud costs than on-premise | Classify workloads with 6 R's framework |
| Skipping security planning | Data breach, compliance violation | Step 4 before Step 6 |
| No rollback plan | Stuck if migration fails | Test rollback for every critical workload |
| Underestimating data transfer costs | Bill shock | Calculate egress costs in TCO |
| Not training the team | Shadow IT, manual processes return | Budget for cloud certification training |
Planning a cloud migration? Book a free assessment with Aquarious Technology. We'll audit your current infrastructure and provide a migration roadmap with detailed cost estimates - no obligation.
Planning a cloud migration?
Book a free assessment with Aquarious Technology. We'll audit your current infrastructure and provide a migration roadmap with detailed cost estimates - no obligation.