Migrating a live environment from one cloud platform to another is challenging but can yield quite some benefits. To ensure a smooth and controlled transition, we developed a six-step factory approach to migrate from one cloud to another.

There are many reasons to consider moving your workload from one cloud provider to another. The most common arguments for this ‘cloud hopping’ are:

• It optimizes cloud costs through clever resource usage
• It reduces dependency on one cloud provider
• It can provide better service regarding pricing and service level agreements (SLAs)
• It helps facilitate company mergers when different cloud providers are contracted

The first step in our migration process is the assessment. The goal of this stage is to take an inventory of the scope of migration. An important part of this step is to sit down and talk to each application owner and technical application manager, to get a full picture of the application and its footprint and interfaces.

Based on the assessment, we then determine which strategy to follow for the migration. There are three basic approaches when migrating from cloud to cloud:

• Lift and shift migration
• Application redeployment, application reinstallation and data migration
• Application redeployment and application reinstallation

The best suited approach depends on several factors, such as how much downtime is possible (or allowed), and the effort it takes to redeploy an application.

After the assessment and strategy selection, the third step is to validate these choices – for example, we check whether any targeted cost reduction will indeed occur. This will lead to the decision to move forward or not.

Next is the actual migration. We always automate the migration pipeline as much as possible. Cloud vendors often provide standard tools to help with this, but custom work remains necessary. Automation speeds up the process and reduces the chance of user errors. After the migration, the new environment goes through an extensive testing phase before finally being signed off by the owner.

For one of our customers, we successfully migrated over 40 applications from Azure to AWS using this approach. Read about the lessons we learned and details on the migration pipeline in the full article.