Cloud Migration Strategies
What Cloud Migration Strategies Are
Cloud migration strategies are the approaches an organisation uses to move applications, data and infrastructure from on-premises servers or another environment into the cloud. Each strategy trades speed and cost against how much the application changes and how much cloud benefit it gains.
Industry frameworks usually describe five or six standard options. The main ones differ mostly in how much of the application is changed during the move. The right choice depends on the application's design, its business value, the deadline and the skills available. Moving everything at once is rarely the first decision. For the starting point, see cloud vs on-premises infrastructure.
The Main Approaches: Lift and Shift to Refactor
The most common approaches are listed below, roughly from least to most change.
- Rehost (lift and shift): the application moves to cloud virtual servers with little or no change to its code. It is usually the fastest route, but it keeps the old design and may not reduce costs or improve resilience.
- Replatform (lift, tinker and shift): the application moves with small optimizations, such as switching its database to a managed database service. The core code stays the same.
- Refactor (re-architect): the application is redesigned to use cloud features such as managed services, containers or serverless functions. It can gain the most, but it takes the longest and carries the most risk. See what cloud-native design means.
- Repurchase: the application is replaced with a commercial software-as-a-service product.
- Retire or retain: applications no longer needed are shut down, and those that should stay where they are remain on-premises for now.
A Real-World Comparison: One Application, Three Paths
Suppose a company runs an internal order-tracking application on aging physical servers. The application is stable but hard to scale, and it stores data in a self-managed database that the team struggles to back up.
A rehost would move the servers into cloud virtual machines quickly. The team gets cloud hosting but keeps the same server and database work. A replatform could go further by moving the database to a managed database service, which reduces that workload while the application code stays the same. A refactor would split the application into services that scale separately. That is the most rewarding option, but it needs more development time and testing.
The right choice depends on the goal. If the server contract is ending soon, rehosting may be the safe first step, with later improvements scheduled afterwards.
Frequently asked questions
What is the fastest cloud migration strategy?
Usually rehosting, also called lift and shift, because it changes the least code and configuration. Speed comes with a cost: the application keeps its current design and may not save money or improve reliability. Rehosting is often chosen when a data center lease is ending or a fixed deadline applies.
Should a company migrate everything to the cloud at once?
Most organisations do not. A phased approach moves low-risk applications first, lets the team learn from them and then moves critical systems. Some workloads may stay on-premises because of latency, regulation or cost, which is why hybrid setups are common. Watch for vendor lock-in when choosing proprietary services during a move, as explained in what vendor lock-in is.