Migrating legacy applications to the cloud – how do you do it right?

Jerzy Zawadzki - Chief Technology Officer
7 minutes read

Migrating legacy applications to the cloud – how do you do it right?

Migrating legacy applications might sound like a process that's never-ending – but that's the case only if you don't know how to tackle it.

Truth is, with the right approach, it's a straightforward journey.

This article will guide you through the key steps and strategies, turning a complex task into a clear path towards efficient cloud integration.

Types of cloud migration

Data migration needs vary by company, so there are several ways to migrate applications to the cloud:

  • First, there's on-premises to cloud migration, resembling switching from a physical office space to a virtual one.
  • Then, there's cloud-to-cloud migration, which means switching from one cloud service provider to another.
  • Lastly, cloud to on-premises is a less common scenario based on moving some virtual operations back to a physical location.

Therefore, at the outset, the organization should consider what type of migration it wants or needs to perform.

Gartner’s "5 Rs" cloud migration strategy model

In addition to the above-mentioned types of cloud migration paths, there are different cloud migration strategies. Gartner, a big name in the IT world, developed a nifty model called the "5 Rs" to help businesses figure out their cloud migration strategy. Here we have:

Rehost (“Lift and Shift”)

This is the simplest form. Imagine just lifting your applications and data and dropping them into the cloud as they are, without modifications. It's quick and straightforward, but doesn't take full advantage of what the cloud offers.


This is about tweaking and optimizing your applications to better suit the cloud environment. You change their architecture to make them a better fit. It's more effort than just lifting and shifting, but it can really pay off.


Here, you make a few more changes than just lifting and shifting, but not as many as refactoring. So, in this case, you move your apps and slightly modify them without changing their original functionalities.


This is about starting from scratch – building a new application specifically for the cloud. It's a lot of work, like building a new house, but you get something that's exactly right for your needs.


Finally, this means ditching the old application and switching to a new, cloud-native solution.

Let's focus on the first three: rehost, refactor, and replatform.

These are the most common approaches and offer a good balance between required effort and benefits.

1. The lift and shift (rehost) migration approach

In the “lift and shift” approach, you're basically taking your existing applications and data and moving them to the cloud as they are, without any major modifications. It's like relocating your entire IT infrastructure to a cloud environment but keeping everything else the same.

Advantages of lift and shift

  • No major changes are needed. The beauty of this approach is its simplicity. You don't need to redesign your applications or make big changes to your infrastructure. You just move all of your necessary data and applications without worrying about adjusting them.
  • Easy migration of core services, which are crucial for your IT environment. They will not suffer or lose important elements.
  • Simplified compliance and security management. Since you're not really changing anything, your compliance and security measures remain largely the same.

Disadvantages of lift and shift

  • Not fully leveraging the cloud. Lift and shift doesn't let you take full advantage of all the features that the cloud offers. For example, advanced cloud-native features like serverless computing and cost optimization allow for more efficient resource usage and billing models.
  • Potential performance issues. Sometimes, applications that were not originally designed for the cloud might face performance or latency issues once they're moved.
  • Risks with existing problems. If your applications have any existing issues, these will simply move with them to the cloud.

In a nutshell, lift and shift is like relocating your IT setup to a new cloud environment with minimal changes. It's quick and relatively easy, but it might not let you fully enjoy the new, advanced environment you've migrated to.

2. The refactoring migration approach

Refactoring means adapting and optimizing your existing applications to make them more compatible and efficient in the cloud environment. It's therefore not just about moving to the cloud, but ensuring your applications can fully utilize the cloud's capabilities.

Advantages of refactoring

  • Long-term cost savings and scalability. Once refactored, your applications can run more efficiently in terms of resource usage, which leads to cost savings in the long run.
  • Adaptability to changing requirements. Cloud-native applications are more flexible. You can easily update or modify them to meet new requirements and business needs.
  • Enhanced resilience through cloud-native architectures. By refactoring, you can take advantage of cloud-native features like microservices and containerization, which enhance the resilience and reliability of your apps.

Disadvantages of refactoring

  • Risk of vendor lock-in. When you tailor your applications to a specific cloud provider's architecture, you can become too dependent on them.
  • Time and resource-intensive. Refactoring is not a quick fix. It's a significant undertaking that requires time, resources, and careful planning. Think of it as a full-scale home renovation project.
  • Requires advanced skills. You need a team with advanced coding and DevOps skills to refactor applications effectively.
  • High risk of errors. With so many changes happening, there's a greater risk of introducing errors in code, configuration, and/or infrastructure.

Refactoring in cloud migration is like giving your applications a complete makeover to ensure they don’t just fit into the cloud environment, but thrive in it. While this offers significant benefits, it's a path that requires careful consideration due to its complexity and potential risks.

3. The replatforming migration approach

Replatforming is like giving your car a few upgrades to enhance its performance but not changing the model itself. This is similar with cloud migration – replatforming means making modifications to your applications to take advantage of the cloud without a complete overhaul or redesign.

It's the middle ground between a basic lift and shift and the more intensive refactoring.

Advantages of replatforming

  • Cost-effective with minimal code changes. Few modifications makes it an efficient way to improve your applications for the cloud.
  • Gradual scaling and experimentation. This approach allows you to dip your toes in the water. You can start small, test how your applications perform in the cloud, and then scale up as needed.
  • Leverages cloud-native functionalities. Even with minimal changes, replatforming lets you start using features like auto-scaling, which automatically adjusts resources based on demand.

Disadvantages of replatforming

  • Potential for scope creep. Sometimes, what starts as a small project can grow into something much bigger. That's why you need to be able to adapt the environment to your future needs.
  • Limitations in using specialized cloud components. While replatforming allows for some cloud functionality, it doesn't fully embrace all of the specialized components of cloud computing.
  • Necessity for basic automation. To really benefit from replatforming, you need to have some level of automation in managing your cloud environment.

Broadening perspectives on cloud migration

When we talk about migrating legacy applications to the cloud, it's crucial to understand that there's no one-size-fits-all solution.

These strategies have a unique set of benefits and challenges, and the choice largely depends on your organization's specific requirements, technical capabilities, and strategic goals.

Best practices for migration from legacy systems to the cloud

Here are our best practices for legacy application migration to cloud.

Assess your needs

Before deciding on a cloud strategy, thoroughly assess your current infrastructure, application portfolio, and business objectives. What works for one organization may not work for another.

Balance the cost and benefit

Lift and shift may seem cheaper initially, but it might not offer long-term cost efficiency. Refactoring and replatforming can require more investment upfront, but it often leads to greater savings and efficiency in the long run.

Prepare for future

The digital landscape is constantly evolving. It’s crucial to choose a cloud migration strategy that not only addresses current needs, but also positions you well for future advancements.

Understand cultural shift

Moving to the cloud is not just a technical change but also a cultural one. It requires a shift in mindset and operation that embraces agility, innovation, and continuous improvement.

Develop your skills or hire professionals

As you move to more advanced cloud strategies, the need for skilled professionals in cloud computing, DevOps, and cybersecurity becomes more pronounced. Investing in training and development is key.

Stay agile

The cloud environment is dynamic, thus being able to adapt and respond to new technologies and market changes is a must.

The cost of migrating legacy applications to the cloud

Legacy application migration to the cloud is indeed an expensive and complex venture. It's not just about financial outlay – the process demands substantial time, extensive resources, and the involvement of skilled experts.

Undertaking such a migration means preparing for significant investment in multiple areas. However, an effective strategy to manage these costs and complexities is to collaborate with a top software development agency like Polcode that has comprehensive resources and a team of experienced professionals.

Polcode will dedicate their time to handling the entire migration process for you. This approach not only results in substantial savings for your organization, but also ensures a seamless and high-quality transition to a secure cloud environment and full utilization of technological potential.

So, thanks to entrusting this intricate task to Polcode, you can expect cost efficiency, a perfectly-executed migration, reduced risk of error, taking full advantage of technological opportunities, and positioning your business at the forefront of technological advancement.

Migrating from legacy systems to the cloud: key findings

When it comes to migrating legacy applications to the cloud, there are three key approaches: “lift and shift” (rehost), refactoring, and replatforming.

In short:

  • Lift and shift is like moving your possessions to a new house. It's quick and easy, but doesn't fully utilize the new space.
  • Refactoring is like renovating your house to make it more efficient and suitable for your lifestyle. It requires more effort and investment but can enhance the functionality and performance of your apps in the cloud.
  • Replatforming strikes a balance between the two. It's akin to making selective upgrades, improving certain aspects, and being efficient without undertaking a full-scale renovation.

It is important to note that each method has its own advantages and challenges. The choice depends on various factors, such as your organization's needs, the nature of your legacy applications, available resources, and long-term business objectives.

We have also detailed some best practices that you can follow to take the most suitable approach to data migration for your needs. Among the most important are:

  • Align your migration strategy with your broader business goals. Whether it's improving performance, reducing costs, or enhancing scalability, the approach you choose should directly contribute to these objectives.
  • Consider the long-term impact of your migration strategy. Refactoring, for instance, may be more resource-intensive initially but can offer greater flexibility and cost savings in the long run.
  • Cloud migration is not just a technical shift but also an organizational one. It may require changes in your team's skill sets, workflows, and even the company culture.
  • The technology landscape is constantly evolving. Be open to adapting your strategy as new cloud technologies and best practices emerge.

Choose the best migration strategy for your business and reap all of the benefits from it. And if you need any help with IT legacy systems modernization, reach out to Polcode – our experience can help you improve your operations and online presence.

On-demand webinar: Moving Forward From Legacy Systems

We’ll walk you through how to think about an upgrade, refactor, or migration project to your codebase. By the end of this webinar, you’ll have a step-by-step plan to move away from the legacy system.

moving forward from legacy systems - webinar

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