Migration is not one technical task.

It is a decision about how much of the existing system should survive.

That is why the 6 Rs are useful: rehost, replatform, refactor, rebuild, replace, and retire.

Each one solves a different problem.

Rehost: Move the System With Minimal Change

Rehosting is the simplest migration path.

You move the application to a new environment and change as little as possible.

Typical examples:

On-prem VM

↓

Cloud VM

or:

Old hosting environment

↓

New infrastructure

Best when

the application is stable,

infrastructure is the main problem,

you need to leave a data center quickly,

time is limited,

architectural change is not the immediate priority.

Watch out for

You are moving existing problems too.

If the application is hard to deploy, tightly coupled, or inefficient, those issues usually remain.

Rehosting changes where the system runs.

It does not automatically modernize how the system works.

Replatform: Improve the Environment Without Rebuilding

Replatforming…