What is Cloud Migration?
Cloud migration is the process of moving data, applications, and IT resources from on-premises servers or one cloud environment to a public cloud provider’s infrastructure—or between cloud providers. It works by assessing current workloads, selecting a migration strategy for each asset, transferring data and applications in planned batches, and then testing and optimizing performance in the new environment.
The main benefits of cloud migration include significant cost savings on physical data center maintenance, elastic scalability, improved security, better performance through globally distributed infrastructure, and stronger support for AI and machine learning (ML) workloads. Organizations use cloud migration to modernize legacy systems, reduce technical debt, improve disaster recovery, and build the cloud-native foundation that AI adoption requires.
Cloud migration has 7 recognized strategies—rehosting, relocating, refactoring, replatforming, repurchasing, retiring, and retaining—and covers 6 main migration types: database migration, application migration, hybrid migration, data center migration, cloud-to-cloud migration, and workload-specific migration. The process follows structured phases: assess, mobilize, and migrate and modernize. This article covers cloud migration definitions, benefits, strategies, types, steps, and common challenges—plus how AWS, Azure, and Google Cloud Platform (GCP) support the migration process.
Cloud Migration Definition
Cloud migration is the process of moving applications and data from one location—often a company’s private, on-premises servers—to a public cloud provider’s servers, but it also includes moving resources between different clouds.
Organizations run cloud migrations to shift from self-managed IT infrastructure in on-premises data centers to cloud provider infrastructure—in a planned, nondisruptive way. A cloud migration strategy defines which workloads move, in what order, using which approach, and on what timeline. Cloud migration benefits include reducing IT costs, improving performance and security, and enabling faster access to new technologies like AI Agents, Generative AI (GenAI), and Intelligent Automation.
Key Takeaways
• Cloud migration moves data, applications, and workloads from on-premises infrastructure or one cloud to another cloud environment.
• There are 7 cloud migration strategies: rehosting, relocating, refactoring, replatforming, repurchasing, retiring, and retaining.
• Cloud migration delivers 8 main benefits: cost efficiency, scalability, security, performance, sustainability, compliance, backup and recovery, and simplified management.
• The 3 core phases of cloud migration are: Assess, Mobilize, and Migrate and Modernize.
• Common challenges in cloud migration include technical complexity, skills gaps, cost overruns, security risks, and business downtime—all manageable with proper planning.
• 75% of organizations are expected to adopt cloud-based data infrastructure by 2026, driven by AI workload demands and digital transformation goals.
What are the Benefits of Cloud Migration?
There are 8 main benefits of cloud migration for organizations moving from on-premises data centers to cloud infrastructure.
Cost Efficiency / Optimized Costs
Cloud migration delivers significant cost savings by eliminating the expenses of maintaining physical data centers—hardware procurement, power, cooling, and physical security. Organizations that shift to a public cloud pay only for the resources they use, which removes the need to provision capacity for peak demand that sits idle the rest of the time. The savings in human resources are also significant: skilled IT staff freed from data center administration tasks can focus on business development instead. Cloud providers typically offer multiple pricing models, including free tiers, reserved capacity discounts, and pay-as-you-go rates, so organizations choose the most cost-effective option for each workload.
Scalability / Flexibility and Scalability
Cloud infrastructure scales up or down in response to workload demand without hardware procurement delays or capital expenditure. Organizations adjust IT resources dynamically, so applications perform well during peak traffic and don’t waste resources during off-peak periods. Cloud providers offer a broader range of services and tools—including AI Infrastructure, ML platforms, and Data Engineering pipelines—than most organizations can build for themselves on-premises.
Security / Enhanced Security
Major cloud providers like Amazon Web Services (AWS), Microsoft Azure, and Google Cloud Platform invest heavily in data security measures, including encryption at rest and in transit, multi-factor authentication (MFA), identity and access management (IAM), and regular third-party security audits. Cloud providers take responsibility for security of the cloud infrastructure itself, while organizations control configurations and access policies. Multiple backup and disaster recovery mechanisms protect digital assets from loss, breach, or corruption.
Performance
Cloud providers operate globally distributed data centers and content delivery networks (CDNs), so users receive content from the geographically closest server—reducing latency and increasing load times. Applications in the cloud run on current server and network technology, delivering faster processing speeds than aging on-premises hardware. Cloud migration improves application performance consistency and supports the low-latency, high-throughput requirements of AI and Predictive Analytics workloads.
Sustainability
Cloud providers achieve higher energy efficiency than traditional data centers through optimized server utilization, energy-efficient hardware, and advanced cooling techniques. Organizations that migrate to the cloud reduce their direct energy consumption and carbon footprint compared to running equivalent on-premises infrastructure, with lower power and cooling costs as a direct result.
Compliance
Cloud providers build compliance certifications—including SOC 2, ISO 27001, HIPAA, GDPR, and FedRAMP—into their infrastructure and tooling. Organizations inherit these certifications for their cloud workloads and use cloud-native tools to automate compliance enforcement, audit logging, and data sovereignty adherence. Automated compliance enforcement reduces the manual effort required to pass security audits and maintain regulatory standards.
Backup, Recovery, and Failover
Cloud infrastructure provides built-in disaster recovery mechanisms that are cost-prohibitive to replicate on-premises. Organizations configure automated backups, cross-region data replication, and failover routing so that systems recover quickly when incidents occur. Cloud-based disaster recovery reduces recovery time objectives (RTOs) and recovery point objectives (RPOs) compared to traditional backup approaches, maintaining business continuity with minimal downtime.
Simplified Management and Monitoring
Cloud providers offer centralized dashboards, automated patching, unified monitoring, and managed services for databases, containers, and serverless functions—reducing the operational burden on internal IT teams. Data Governance, Business Intelligence (BI), and MLOps tooling integrate directly with cloud infrastructure, giving organizations end-to-end visibility into their data and application estate from a single control plane.
What are Cloud Migration Strategies?
There are 7 cloud migration strategies organizations use for successful cloud adoption. The right strategy for each application depends on business objectives, technical constraints, the application’s criticality, and the desired long-term outcome.
Rehosting
Rehosting—also called lift-and-shift—moves an application to cloud infrastructure as-is, with no changes to architecture or code. Rehosting is the quickest migration approach and suits applications that are not tightly coupled to underlying hardware. The tradeoff is that rehosted applications don’t take advantage of cloud-native features, so cost and performance improvements are limited compared to refactored or replatformed workloads.
Relocating
Relocating—or lift-and-optimize—moves applications to the cloud without significant initial changes, then transitions them to cloud-centered services post-migration. For example, a database relocated to the cloud might later move from a hosted virtual machine (VM) to a fully managed database service. This approach delivers some cloud-native benefits without requiring extensive upfront refactoring.
Refactoring
Refactoring rearchitects applications to take full advantage of cloud-native capabilities. This includes decomposing monolithic architectures into microservices, replacing legacy modules with managed cloud services, and adopting serverless function deployment patterns. Organizations choose refactoring when applications need new features, improved scalability, or performance that the existing architecture cannot support.
Replatforming
Replatforming—or lift, tinker, and shift—is the middle path between rehosting and refactoring. Specific components move to cloud-based services that offer advanced features, but the application architecture stays largely intact. For example, a manual data management environment might be replaced with an autonomous cloud database service that includes built-in ML models and automatic updates—without redesigning the entire application.
Repurchasing
Repurchasing replaces an existing application with a software as a service (SaaS) alternative. Rather than migrating the application to the cloud, organizations retire the current software license and adopt a cloud-based product that meets the same need. Repurchasing works well for non-core applications like email, customer relationship management (CRM), and HR management systems.
Retiring
Retiring decommissions applications and assets that are no longer needed or are outdated. Turning off unused resources reduces migration scope, lowers cloud migration costs, and simplifies the overall process. Retiring is distinct from repurchasing: retiring eliminates the asset entirely, while repurchasing replaces it with a different product.
Retaining
Retaining—or revisiting—holds off migration for applications that have recently undergone major upgrades or where the business case for migration is unclear. Organizations keep these workloads on-premises or in their current environment and reassess them on a defined schedule. Retaining is a deliberate decision, not a default—each retained application needs a documented reason and a future review date.
What are the Types of Cloud Migration?
There are 6 types of cloud migration, varying by what is being moved and where it is going.
Database Migration
Database migration transfers a database from one environment to another—on-premises to cloud, one cloud provider to another, or to a new database engine. This process requires careful data mapping and schema evolution to avoid errors, and careful timing to minimize downtime. There are 3 common database migration approaches: replication-based migration (keeping source and target in sync during cutover), full export and import via physical device, and extract-transform-load (ETL) over a secure network connection.
Application Migration
Application migration moves existing applications from on-premises infrastructure or one cloud environment to another. This process uses rehosting, replatforming, or refactoring depending on the application’s architecture and cloud compatibility. The most complex application migrations involve legacy mainframe systems—often written in COBOL—where ensuring mission-critical functions continue without disruption requires extensive testing and a phased migration approach.
Hybrid Migration
Hybrid cloud migration moves some workloads to the cloud while keeping others on-premises. Organizations use this approach to preserve existing infrastructure investments while accessing cloud capabilities for specific workloads—like moving peak traffic handling to the cloud while keeping sensitive data on-premises. Hybrid migration often serves as the first step toward a complete data center migration, with orchestration tools providing connectivity between the on-premises and cloud environments.
Data Center Migration / Complete Data Center Migration
Data center migration moves an entire on-premises infrastructure—servers, storage, networking, databases, and applications—to the cloud. This migration type requires all 7 migration strategies applied across different asset categories, plus thorough planning, dependency mapping, and security validation. Organizations choose this migration to reduce operational costs, eliminate physical data center maintenance, increase scalability, and improve disaster recovery capabilities.
Cloud-to-Cloud Migration
Cloud-to-cloud migration moves workloads from one cloud provider to another. Organizations make this move for 4 primary reasons: cost savings with a different provider’s pricing model, access to better-fit services (such as AI and ML tools on a specific platform), regulatory requirements that mandate specific data residency, or changes to service level agreements. Vendor lock-in avoidance is a key design consideration in cloud-to-cloud migration—using cloud-agnostic architectures and containerization strategy adoption reduces the cost of future provider changes.
Workload-Specific Migration
Workload-specific migration moves selected databases, mainframes, or application components to the cloud without migrating the entire environment. Organizations use this type to capture specific benefits—lower cost on a particular workload, better performance for a specific service, or compliance requirements for a defined dataset—while keeping the broader migration scope manageable.
What are the Steps in Cloud Migration?
Cloud migration follows 3 broad phases at AWS, each containing specific steps. Other frameworks—including Azure and IBM cloud migration methodologies—add stages for architecture design, governance, and ongoing management. The steps below consolidate the most complete cloud migration process.
Assess / Assess and Plan
Assess the current IT portfolio—applications, workloads, databases, and data—before any migration begins. The assessment phase produces a cloud readiness and migration assessment that identifies what to migrate, what to retire, and what to retain. Key activities in this phase include:
• Cataloging and categorizing all applications and data assets
• Analyzing application dependencies and interdependencies
• Evaluating security and compliance requirements per workload
• Estimating migration costs and potential savings
• Prioritizing workloads by business value and migration complexity
Mobilize
Build the team, tools, and processes needed to execute migration after the assessment is complete. The mobilize phase prepares both the technical environment and the organization for migration at scale. Key activities include building a core cloud team with cloud architects and developers, developing a migration plan with timelines and milestones, setting up the target cloud environment with correct security configurations, and running pilot application migrations to validate the strategy before full-scale execution.
Design the Target Cloud Architecture
Design how applications, data, and infrastructure will be organized in the cloud environment. This step defines scalable and resilient cloud architectures, networking and security configurations, appropriate cloud services, cost optimization structures, and data backup and disaster recovery mechanisms. A well-designed target architecture prevents post-migration rework and reduces the risk of performance or security gaps.
Run the Migration
Execute the transfer of IT infrastructure to the new cloud environment. Depending on the strategy (rehosting, replatforming, or refactoring), the execution process involves provisioning virtual machines, storage, and network resources; replicating or migrating data to the cloud; and deploying and configuring applications in the new cloud infrastructure. Batch-based migration groups similar workloads together to accelerate progress and reuse proven patterns.
Test and Validate
Test migrated applications and data thoroughly before decommissioning on-premises equivalents. There are 4 types of testing to conduct: functional testing (to confirm application behavior), performance and load testing (to verify scalability under traffic), security testing (to identify vulnerabilities and confirm compliance), and user acceptance testing (to validate the end-user experience). Resolve all identified issues before cutover.
Optimize and Maintain Cloud Infrastructure
Shift focus to optimizing cloud resources and configurations after migration is complete. This step includes fine-tuning applications, installing security measures and access controls, setting up monitoring and alerting, streamlining resource usage, and establishing governance processes. Cloud adoption requires continuous performance monitoring—organizations update software, scale based on demand patterns, and monitor cloud costs to maintain cost-effectiveness over time.
Govern / Foundation Setup and Governance
Anchor migration and ongoing operations with strong governance. A centralized structure—such as a Cloud Centre of Excellence or Cloud Transformation Office—provides oversight to keep scope under control, manage risk, and maintain business alignment. Governance frameworks define provisioning policies, tagging standards, cost allocation rules, and security baselines that apply across all cloud workloads.
Manage
Operate and improve the cloud environment on an ongoing basis after migration. Management activities include monitoring application and infrastructure performance, managing cloud costs through FinOps practices, applying security patches and updates, and continuously adopting new cloud capabilities—including AI Infrastructure, Data Engineering pipelines, and MLOps tooling—as they become available.
What are the Challenges in Cloud Migration?
There are 8 common challenges in cloud migration. Without proper planning, cloud migrations run over budget, miss timelines, and create security or compliance risks.
Technical Complexity
Legacy systems in on-premises environments often have interdependencies that make migration complex. Moving one application without its dependencies disrupts operations. Older systems may be incompatible with cloud environments and require significant refactoring or complete redevelopment. Legacy system decoupling—separating tightly coupled components before migration—reduces this risk but requires upfront engineering investment.
Scalability Challenges
Migrating large application estates requires staged effort and planning. Transferring large data volumes to the cloud takes time with limited network bandwidth. Some interdependent migrations temporarily require applications to go offline, impacting business operations. Rolling back to on-premises if post-migration issues arise is complex and time-intensive, making thorough pre-migration testing essential.
Skills Gap / Organizational Adoption and Training
Cloud platforms require different skills than traditional IT environments. In-house teams accustomed to on-premises infrastructure often lack cloud architecture, DevOps, CloudOps, and Automation Enablement expertise. Organizations must train existing staff or hire new talent with cloud skills. Beyond technical training, internal culture often needs to shift—teams need to embrace cloud-native tools and processes to get migration value from the investment.
Planning
Inadequate planning is the most common root cause of cloud migration failure. Organizations that skip the assessment phase or underestimate application dependencies encounter unexpected costs, delays, and downtime. A detailed cloud migration roadmap—covering workload prioritization, timelines, milestones, rollback procedures, and stakeholder communication—reduces planning-related failures.
Cost
75% of cloud migrations run over budget and 38% miss their timelines. Cost overruns typically stem from underestimating data transfer costs, over-provisioning cloud resources post-migration, and failing to implement cloud cost optimization and FinOps practices from the start. Organizations that model costs thoroughly in the assessment phase and apply tagging and budget alerts from day one control migration costs more effectively.
Security and Compliance
Cloud security operates on a shared responsibility model: cloud providers secure the infrastructure, while organizations secure configurations, data, and access controls. Misconfigurations—publicly exposed storage buckets, overpermissioned identities, and unencrypted data transfers—are the most frequent source of cloud security incidents. 53% of organizations find cloud compliance too difficult to manage without dedicated tooling and automated compliance enforcement.
Business Downtime
Zero downtime migration requires careful dependency mapping, parallel-run periods, and phased cutover planning. Unplanned downtime during migration disrupts business operations, damages customer experience, and erodes confidence in the migration program. Organizations achieve zero downtime migration through live data replication, blue-green deployment patterns, and staged traffic cutover rather than hard-cutover approaches.
Migration Partner/Vendor Selection
Choosing the right migration partner affects both the speed and outcome of cloud migration. Partners with proven cloud migration experience—including AWS Migration Competency partners and Azure Expert MSPs—bring repeatable frameworks, automation tooling, and cross-industry knowledge that reduce risk. Organizations should evaluate partners on their experience with specific migration types, their governance approach, and their track record with similar workload complexity.
Modernization-Led Cloud Migration: The Missing Step in Seizing the AI Opportunity
AI tools are driving a rapid increase in the volume, complexity, and intensity of cloud workloads. Gartner projects a five-fold increase in AI-related cloud workloads by 2029, consuming half of all compute resources. Only organizations with a modern cloud foundation will keep pace with AI-driven competitors.
Two patterns block AI readiness in practice. Some organizations stayed on-premises, held back by monolithic systems and accumulated technical debt. Others moved to the cloud but did so via a lift-and-shift approach that transferred legacy problems into the new environment without modernizing. Both groups face the same result: their environments cannot support AI at scale. AI workloads require elasticity, modern security patterns, clean data integrations, and real-time data access—capabilities that legacy or superficially migrated applications cannot provide.
Modernization-led migration solves this by addressing architectural issues before or during migration. The starting point is a complete inventory of the application estate, grouped into 3 categories: business-critical applications (those that directly affect revenue or customer experience), business-enabling applications (those that support operations and processes), and corporate and support applications (used across HR, finance, and internal teams). This grouping drives prioritization and identifies applications that are candidates for retirement.
Each application then gets matched to the right modernization strategy—rehost, replatform, refactor, rearchitect, or replace—based on criticality, cost profile, performance needs, technical debt, and long-term business value. The goal is sustainability, not speed. Modernization should leave applications more resilient, flexible, and secure than before.
How can AWS support your cloud migration process?
AWS supports cloud migration with a suite of tools and programs that cover every phase of the migration process—from initial assessment through ongoing optimization. There are 6 key AWS migration tools and programs:
• AWS Application Discovery Service: Gathers information about source servers to support migration planning.
• AWS Application Migration Service: Provides an automated approach for rehosting servers to AWS cloud.
• AWS Database Migration Service (AWS DMS): Migrates databases to AWS quickly and securely with replication from source to target.
• AWS DataSync: Automates moving file and object data between on-premises systems and AWS storage services.
• AWS Migration Acceleration Program (MAP): A comprehensive migration program built on experience migrating thousands of enterprise customers to cloud.
• Migration Evaluator: Delivers accurate, data-driven recommendations for right-size and right-cost computing before migration begins.
Cloud Migration Benefits
Cloud migration delivers 8 measurable benefits: cost efficiency through elimination of physical data center costs, elastic scalability without hardware investment, enhanced security through provider-managed infrastructure and tooling, improved performance through distributed global infrastructure, sustainability through energy-efficient operations, compliance support through built-in certifications and automated enforcement, disaster recovery through cross-region replication and failover, and simplified management through centralized monitoring and managed services.
Organizations that combine cloud migration with modernization unlock a 9th benefit: AI readiness. A modernized cloud foundation provides the architecture, data integration, and compute elasticity that AI Agents, GenAI Consulting applications, Machine Learning Solutions, and MLOps pipelines require to deliver business value at scale.
Conclusion
Cloud migration is the process of moving data, applications, and IT resources from on-premises servers to a public cloud provider’s infrastructure—or between cloud environments. It delivers 8 core benefits: cost efficiency, scalability, security, performance, sustainability, compliance, disaster recovery, and simplified management. Organizations that combine migration with modernization build the cloud-native foundation required for AI adoption at scale.
The 7 cloud migration strategies—rehosting, relocating, refactoring, replatforming, repurchasing, retiring, and retaining—give organizations a framework to match each application to the right approach based on its technical complexity, business criticality, and long-term value. The 3-phase migration process of Assess, Mobilize, and Migrate and Modernize provides a structured path from current-state inventory to optimized cloud operations.
75% of cloud migrations run over budget without proper planning, and 95% of organizations face cloud skills gaps. Addressing these challenges requires a thorough assessment phase, a clear migration strategy and target architecture design, strong governance, and either internal cloud expertise or an experienced migration partner. Organizations that plan thoroughly and modernize alongside migration reduce cost overruns, minimize downtime, and position themselves to use AI, Data Science, Predictive Analytics, and Generative AI capabilities as soon as migration is complete.
