Types of Cloud Migration: On-Prem to Cloud, Cloud-to-Cloud and More

What Is Cloud Migration? 

Cloud migration is the process of moving digital business operations, such as applications, data, and infrastructure, from local on-premises systems to cloud-based environments. This shift enables organizations to take advantage of scalable resources, cost savings, and capabilities offered by cloud service providers.

Cloud migration can be broadly categorized into three main types: 

1. On-premises to cloud: This is the most common type of cloud migration, involving moving workloads and data from a company’s own data center or private infrastructure to a public cloud provider. Techniques in this category include:

• Lift and shift (rehosting): Moving applications and data to the cloud without significant changes. This is the fastest migration method but may not fully leverage cloud capabilities. 
• Replatforming: Making minor adjustments to applications to optimize them for the cloud environment while keeping the core architecture similar to the original. 
• Refactoring (rearchitecting): Rebuilding applications from scratch to fully utilize cloud-native features and services. This offers the most flexibility and potential for optimization but is the most time-consuming. 
• Repurchasing: Switching to a cloud-based software-as-a-service (SaaS) solution instead of migrating existing applications. 

2. Cloud to cloud: This involves migrating workloads and data between different cloud providers (e.g., from AWS to Azure) or from a private cloud to a public cloud. Techniques in this category include: 

• Inter-cloud migration: Moving workloads between different public cloud providers. 
• Cloud to on-premise (reverse migration): Migrating data and applications back from the cloud to a local data center. 

3. Cloud to on-premises: This is less common, but involves migrating workloads and data back from the cloud to a company’s own infrastructure. This is also known as “repatriation” or reverse cloud migration. 

Types of Cloud Migration 

On-Premises to Cloud

This is the most common type of cloud migration, where organizations move applications, data, and workloads from in-house servers to a public, private, or hybrid cloud environment. It typically involves one of several approaches: rehosting (lift and shift), replatforming (making minimal adjustments), or refactoring (modifying the application architecture).

How it works:

Migration begins with an assessment of the existing environment, identifying dependencies and workload priorities. Data and applications are then transferred to the cloud using migration tools or services. Some workloads may need to be re-architected to suit cloud-native features, such as autoscaling or distributed computing.

Benefits:

• Reduced infrastructure maintenance
• On-demand scalability
• Lower capital expenditure
• Improved disaster recovery options

Challenges:

• Potential downtime during migration
• Data security and compliance concerns
• Rewriting or modifying legacy applications
• Complexity of integrating cloud services with existing systems

Cloud to Cloud

Cloud-to-cloud migration involves transferring data, applications, or services from one cloud provider to another. This may occur when organizations seek better pricing, performance, compliance, or features from a different provider.

How it works:

The process usually involves exporting data and configurations from the source cloud and importing them into the target cloud. Compatibility between services and formats can be a challenge, so tools that support multi-cloud environments or API integration are often used to simplify the transition.

Benefits:

• Avoiding vendor lock-in
• Access to better features or performance
• Cost optimization
• Improved geographic availability

Challenges:

• Differences in cloud service architectures
• Rewriting infrastructure-as-code or automation scripts
• Downtime or data loss risks
• Complex security configurations and access controls

Cloud to On-Premises

In some cases, organizations may decide to move workloads from the cloud back to on-premises infrastructure. This is often referred to as “reverse migration” or “cloud repatriation.”

How it works:

Data and applications are extracted from the cloud environment and redeployed in on-premises systems. This may require significant reconfiguration, especially if the applications were originally built or refactored for cloud-native services.

Benefits:

• Full control over infrastructure
• Predictable costs over time
• Better compliance with regulatory or data residency requirements
• Lower latency for local users

Challenges:

• Rebuilding infrastructure and services
• High initial hardware and maintenance costs
• Loss of cloud-native features like autoscaling or managed services
• Migration complexity and potential downtime

Key Types of Cloud Migration Strategies 

Rehosting

Rehosting, or “lift-and-shift,” involves moving applications and workloads to the cloud with minimal or no modifications. Typically, this approach migrates existing virtual machines, data, and applications to the cloud infrastructure as-is. Rehosting is attractive for organizations seeking quick migration with limited risk or disruption, especially for legacy systems that don’t require immediate modernization. 

One major advantage of rehosting is its speed and simplicity. Organizations can quickly realize the operational benefits of cloud environments without rearchitecting their applications. However, this method may miss out on optimized performance or cost savings available through native cloud features, since applications aren’t modified for cloud-native operation. Long-term, rehosting often serves as an initial step before subsequent optimization phases.

Replatforming

Replatforming, sometimes called “lift-tinker-and-shift,” modifies certain aspects of applications or infrastructure before migrating them to the cloud. This can involve simple changes such as updating operating systems, swapping out middleware, or leveraging managed database services. The goal is to achieve improved performance, manageability, or cost-efficiency without a full rebuild. 

This strategy strikes a balance between speed and optimization, allowing organizations to benefit from cloud-native features while controlling migration risk and effort. Replatforming is practical for workloads needing modest enhancements to fully capitalize on cloud capabilities but where time or budget constraints rule out major rewrites. It also paves the way for gradual modernization after initial migration.

Repurchasing

Repurchasing refers to replacing existing applications with new, cloud-based solutions, often in the form of SaaS platforms. Instead of migrating legacy systems, organizations adopt completely new applications that are built for cloud delivery. This often involves shifting from custom or on-premises software to standardized products like Salesforce, Microsoft 365, or similar services. 

While repurchasing can simplify IT maintenance and improve scalability, it requires users to adapt to new workflows and potentially migrate historical data. This strategy is common for commodity business functions, such as email or CRM, where specialized customization isn’t critical. The effort lies in organizational change management and ensuring smooth data transition to the SaaS platform.

Refactoring

Refactoring, or re-architecting, is a strategy that involves redesigning and rewriting applications to take full advantage of cloud-native architectures and services. The process addresses limitations in the original design, unlocking scalability, automation, and resilience only possible in the cloud. Refactoring is most suitable for mission-critical or growth-oriented systems requiring a complete overhaul to meet new technical or business demands. 

This is often the most resource-intensive approach, demanding significant investment of time and expertise. However, the payoff can be substantial: applications gain elasticity, improved availability, and advanced security features. By fully leveraging cloud-native patterns such as microservices and serverless computing, organizations position themselves for rapid innovation and long-term competitive advantage.

Retiring

Retiring is the process of decommissioning applications or workloads that are no longer valuable to the organization. During migration planning, businesses often discover legacy systems that have become obsolete, redundant, or inefficient over time. Retiring such systems reduces technical debt, frees up IT resources, and lowers operating costs. 

This strategy is critical for simplifying IT environments and focusing migration and cloud management efforts where they add the greatest value. However, before retiring any workload, organizations must ensure that key business processes or data dependencies are not disrupted and that any essential data is archived or migrated to alternative systems as needed.

Retaining

Retaining refers to keeping certain applications, data, or workloads on-premises or in their current environment rather than migrating them to the cloud. This decision may be driven by compliance requirements, technical constraints, or a lack of business justification for migration. Retention is often a temporary measure while organizations incrementally plan future migrations or until appropriate cloud solutions become viable. 

While this approach may limit immediate cloud benefits, it ensures mission-critical systems remain stable until migration risks are reduced or competing priorities are resolved. Clear identification and periodic re-evaluation of retained assets are important to ensure IT portfolios remain aligned with evolving business goals and technology landscapes.

Relocating

Relocating typically involves moving workloads between cloud data centers or regions within the same cloud provider, often for performance, compliance, or disaster recovery reasons. This differs from migration between environments, as the architecture and service models remain consistent, minimizing technical changes. The primary focus is on shifting resources to new locations to satisfy geographic, regulatory, or operational requirements. 

Relocating workloads is generally less disruptive than other migration strategies since application logic, dependencies, and configurations remain largely unchanged. However, careful planning is necessary to ensure data consistency, continued availability, and adherence to compliance requirements, especially when crossing international boundaries or serving new regions.