Six Rs of cloud migration: The Isotoma approach

When it comes to mapping out your cloud migration strategy, it can be difficult to know where to start. The process will depend in a large part on the type and complexity of the applications you wish to move. So how do you begin?

The six Rs of cloud migration is a good place to start. It refers to six different approaches to getting an application to the cloud, and while it won’t necessarily be the case that you should treat the list as a menu to pick and choose from, it’s good practice to keep them in mind.

You should look first at the current status of your business and your objectives. The best cloud-migration approach for you will be the one that not only solves a problem but prepares you for the future. 

At Isotoma, two of the six (replatforming and rearchitecting) form the foundation for our approach to cloud migration and deliver the outcomes we want to achieve for our clients.

To provide a clear context for these two approaches, first, we’ll explain what the other four Rs of replatforming mean.


Rehosting is basically a ‘lift and shift’ approach. You’re moving your application from an on-premise environment to the cloud without making any modifications to it.


Rather than moving your application to the cloud, here you’re looking for an existing cloud-based or SaaS equivalent. Repurchasing means you decommission your on-premises application and replace it with a cloud-based version.


In the context of your ongoing application development, you may decide that your current on-premise application is no longer fit for purpose. Either it’s too clunky or inefficient for cloud migration or it’s doing things you no longer need.

Therefore you could decide to decommission these applications or consolidate their functions with others.


If you’re heavily invested in your on-premise application and you’re in the middle of working on a project, it may make sense to retain your current application rather than migrate it.

Replatforming and rearchitecting: The Isotoma approach

We mentioned earlier that the Isotoma approach focuses on two of the six Rs: replatforming and rearchitecting. These two categories are closely related and make the most of Isotoma’s unique mix of development and operational experience.

In replatforming, we move an application from a data centre or on-premise to the cloud and incorporate subtle changes along the way. This optimises the application for its new cloud-based environment, irons out any kinks and makes it more stable and scalable.

This highlights a frequently misunderstood aspect of cloud migration. It isn’t primarily about saving money but about adding value. By optimising your application as part of its migration, you get more bang for your buck.

An example of this is AWS’s Aurora system. This is a relational database built specifically for the cloud. It’s significantly faster than both standard MySQL and PostgreSQL databases. At a much cheaper cost, you get the security and reliability of a commercial database readily available. Similarly, the Amazon S3 simple cloud storage system provides advanced functionality at 11 9s of data durability. This translates as 99.99966% of stored data being defect-free.

But if replatforming won’t provide the complete solution you’re looking for, then there’s always rearchitecting.

How rearchitecting works

A business can find itself so heavily dependent on an application that jettisoning it isn’t an option.

But what if this application is getting creaky, with certain characteristics that will be problematic for cloud migration?

The answer is rearchitecting. This approach to cloud migration is also known as refactoring or restructuring. Essentially, it’s a reimagining of the application, like a snake shedding its skin. The objective is to transform it into something fully cloud-native that still achieves what it did before.

This may mean retaining some of its current coding (perhaps using containers) but future-proofing it for the cloud. It represents a complete overhaul of the application to transition its architecture to something that’s fully cloud-functional.

Rearchitecting is especially valuable and beneficial for businesses with existing applications at the core of their operations and even their entire brand purpose. What it offers is an approach to cloud migration that can encompass highly customised and dedicated applications.

How to choose your migration methodology

It’s critical in cloud migration to understand which approach will best enable you to achieve your business objectives.

This is about looking at things in the longer term. Will a relatively simple fix now stand you in good stead for expanding your customer base, for example?

How dependent are you on your applications? To what degree does this tether you to an on-premises arrangement? Is this hampering your scalability and putting a ceiling on your ambitions?

Our replatforming and rearchitecting migration strategies have worked across a far-reaching spectrum of industries, from  music streaming to pensions, the voluntary sector and point-of-sale marketing software.

For more information about cloud migration and exploring your options, please contact the Isotoma team.

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