Cloud Migration Strategies: Choosing the Right Path for Each Application

"Move to the cloud" is not one decision. Each application in your portfolio may need a different approach, and choosing well is the difference between a smooth migration and an expensive one. This guide explains the commonly used strategies and how to decide between them.

The main strategies

• Rehost ("lift and shift"). Move the application as it is onto cloud servers. It is the fastest route and changes the least, but it captures few of the cloud's benefits.
• Replatform. Move with modest changes, for example switching to a managed database. You keep the application's design but reduce operational work.
• Refactor. Redesign parts of the application to use cloud capabilities such as automatic scaling. It costs more up front and can pay back in flexibility.
• Replace. Retire the application and adopt a ready-made product that does the job.
• Retire. Switch off applications nobody needs any more.
• Retain. Leave an application where it is, for now, because of cost, risk or regulation.

How to choose for each application

1. What is its business value? Critical systems deserve careful planning.
2. How is it built? Old or unsupported technology may limit your options.
3. What does it depend on? Databases, files and other systems must move in a sensible order.
4. What are the constraints? Data residency, licenses and downtime tolerance all matter.
5. What is the goal? Cost, resilience, speed of change or all three?

Prepare the foundation first

Before moving anything, set up the environment: accounts and access control, network layout, logging, backup, and a clear approach to cost tracking. Building these once and consistently prevents each migrated application from inventing its own.

Migrate in waves

Start with a low-risk application to prove the process, then move groups of related applications together. For each one: copy the data, test the cloud version alongside the original, agree a cut-over window and keep a rollback plan until the new system has run stably.

Common pitfalls

• Moving everything the same way without assessing each application.
• Ignoring the data: large databases can take longer to transfer than expected.
• Forgetting integrations with other systems and scheduled jobs.
• Leaving resources running and unreviewed, so costs drift upwards.
• Skipping testing of backup and recovery until something goes wrong.

After the move

Migration is the start of operating in the cloud. Add monitoring and alerts, review cost regularly, automate deployment, and revisit rehosted applications later to see whether improving them is now worthwhile.