Hero Cluster

Migration Strategies Basics: Lift and Shift, Refactor, or Replace?

How Is Application Modernization Pushing Migration Strategies in Companies?

Modernizing your applications is one of the first steps in a digital transformation plan in your organization. The modernization process begins with a comprehensive assessment of the company, which includes, among other decisions, the migration of monolithic applications to the cloud. Although this process can be challenging, new technology makes the process easier and more reliable. 

Gartner specifies application modernization services “address the migration of legacy to new applications or platforms, including integrating new functionality to provide the latest functions to the business. Modernization options include re-platforming, re-hosting, recoding, rearchitecting, re-engineering, interoperability, replacement and retirement, as well as changes to the application architecture to clarify which option should be selected.”

And, in case you are not familiar with the term, a monolithic application is “an app that has all or most of its functionality within a single process or container, and it’s componentized in internal layers or libraries.”

You can measure the success of a company’s digital transformation by evaluating how it changed its products and services to digital environments, along with the acquisition of skills tied to these changes. Companies that have become digitally mature utilize information and communication technologies in a significant part of their activities and have the capability and willingness to digitize their processes, functions, and organization.

Why Do Companies Decide to Migrate Their Applications to the Cloud?

cloud computing graphic

Modernizing outdated applications aims to accomplish the following business objectives: 

  • Improving application performance and scalability
  • Increasing availability
  • Eliminating technical debt: “Technical debt is a concept in programming that reflects the extra development work that arises when code that is easy to implement in the short run is used instead of applying the best overall solution.”
  • Improving compliance and security

In general, companies want to enhance the user experience, keep employees productive, and ensure sensitive data is protected. Their applications would benefit from being in the cloud to scale, secure, and comply with these goals. 

However, when decision-makers run into initiatives and processes limited by old and outdated applications, they reach a breaking point: They either stay the same and lose competitiveness or choose to modernize applications, especially business-critical ones, as a priority.

As the pace of digital transformation increases by the minute, companies of all sizes are racing to become more technology-driven. The recent pandemic has only accelerated this process. Forward-thinking businesses will remain viable for decades to come if they use the right mix of modern solutions, techniques, and strategies, becoming more agile and responsive as a result.

Related: Migrating Monolithic Applications to Microservices Architecture

Assessing Legacy Applications

Perhaps you could relate to the previous sections and want to take the next step in migrating your legacy applications to the cloud. In this case, Gartner recommends considering the following factors when assessing the value of modernizing legacy applications.

Business fit

Competitors are modernizing their apps and moving them to the cloud or using SaaS for their solutions. This lets them innovate faster, provide a better customer experience, and recruit the best employees. The longer you wait, the more market share they gain.

Business value

Modern applications benefit from modular architectures or microservices, which allow for easy changes with less risk. Customers can benefit from faster value delivery.


Developers are able to add new features faster with modern applications because the development process is accelerated. Automated building, testing, and releasing builds streamline time-to-market processes.


In modern applications, the running cost is significantly lower because they typically operate on a consumption-based model. Using this method avoids both wasting resources and paying for downtime. In addition, the prices of infrastructure management decrease.


In monolithic systems, adding new features is complicated because of the tight coupling. Yet, it’s also hard to break the coupling and move from a data center to the cloud when modernizing. You have to weigh these pros and cons.


Maintaining legacy systems and modernizing them both carry risks. Businesses should assess the costs, vulnerability, competitiveness impact, and operational consequences before making a decision.

With these concepts, you will be able to evaluate your applications more efficiently and choose the best approach to modernization. This will allow you to make the right decision for your company.

Related: How to Conduct an Application Assessment for Cloud Migration

Lift and Shift, Refactor, Replace, or Another Option?

If you’ve heard only about lift, shift, refactor, and replace, know there are other ways to begin your cloud migration. Here are some ways Gartner explains.


This approach makes the application’s features accessible as services through APIs by encapsulating or separating their data and functions.

In other words, the process creates a more modern interface or API for the existing application and its components making it easier to access by other, newer cloud-native applications but doing nothing to modernize the system or improve the architecture for the future.

You may benefit from encapsulation in the short term because it allows you to move your application to a modern API-driven interface without spending time rewriting it. While it’s a gradual transformation, it is also a stop-gap approach that continues to accrue technical debt and slow down innovation. Thus, in turn, this method comes with some risks, too. Monolithic applications are complicated because of their complexity and size. Without decoupling the logic into microservices, you cannot take advantage of the full benefits of the cloud.


Rehosting refers to moving the application without modifying its code, data, or functionality to another infrastructure, on-premises or in the cloud. 

With rehosting, you can often migrate relatively quickly and test in the cloud in case there is anything wrong. There’s a risk of disruption to business services unless your organization understands this and is ready with enough contingency plans. Additionally, rehosting may lead to poor user experiences early on, which could hurt user retention. 


This migration style means making as few changes as possible to the code for it to run on a new platform, such as the most current operating system. Replatforming does not require you to  manipulate the app’s architecture or functionality.

There is no need to undertake a significant development initiative with replatforming, which makes it cheaper. Taking small steps can be beneficial at first, then you can scale up as needed. The approach also allows you to migrate some workloads to the cloud, run tests on a cloud platform, analyze the results, and then move on to other workloads without committing to a lengthy migration process.

You can leverage the cloud effectively using cloud capabilities such as auto-scaling, managed storage and data processing, infrastructure as code, and more.

This method is not without its risks. One of them is the scope of your work can increase the possibility of turning a replatforming project into a much greater refactoring effort. Limit scope and avoid unnecessary changes to reduce this possibility.

Automation is further necessary since you can’t manage cloud workloads manually after replatforming. As a result, it is essential to invest in automation tools to allow for some flexibility when using the application in the cloud.


Refactoring is the process of reorganizing and optimizing existing code. It lets you get rid of outdated code, reduce significant technical debt, and improve non-functional attributes such as performance, security, and usability. 

This migration strategy matches cloud infrastructure to actual resource requirements, which results in long-term cost savings. Refactoring provides long-lasting ROI by enabling you to scale when required and reducing resource consumption.

Furthermore, by refactoring, you can also adapt to changing requirements since cloud-native, and microservice architectures make it possible for applications to add new features or modify existing ones right away. 

There are a few downsides to consider. First, without automation, this strategy requires a large number of manual resources. It is much more complex than lifting and shifting, so it traditionally has taken much longer for projects to become profitable. You can’t rely on just anyone to refactor because you need a team with advanced coding, automation, and DevOps skills. The code, infrastructure, and configuration are also at high risk of errors. Last, the smallest mistakes in refactoring cause delays, many cost overruns, and service disruptions. Automation can address these issues.


The design of some outdated applications prevents them from working in the cloud because they are just not compatible. When this occurs, it is prudent to rearchitect the application in its entirety. It takes a lot of coding to move to a new application architecture in order to make the most of the apps’ features. 

With the rearchitecture method, you break up applications into smaller, more manageable pieces for subsequent individual adaptations and development. You can transfer each component, or microservice, to the cloud separately.

In addition to requiring significant adjustments, this effort will take a great deal longer and cost more than other alternatives. Nevertheless, the benefits include more flexibility, scaling, and control over the architecture.


Using this approach is a good idea when you need to rewrite a business application entirely but do not wish to alter its specifications or functionality. This is a good approach for companies that have invested significant amounts of time and money in developing their own applications. A business that rebuilds keeps its intellectual property and unique selling propositions, making it a good option for them.

During the rebuilding process, you will be able to engage with customers once again and make your customized applications even better. Unfortunately, this approach requires substantial time and expense investment, as well as considerable expertise. 


This solution offers to replace the application with a brand new version of the software or SaaS service that will take into account any further requirements, user requests and perhaps even use a different technology stack.

In replacement, you can compare different apps and get the ones that work best for your business. If you find something that works better, you can switch apps relatively easily. With the replace approach, the app’s developer is responsible for updating, improving, and securing your application with the replace approach. This can also help relieve you of other migration concerns.

On the other hand, replacing old systems can be problematic for employee engagement due to users becoming attached to the old systems since they are accustomed to using them. Managing change and collaborating with your user base is vital, or you might have a hard time while they adapt. Without custom apps, you might lose future ROI, and you’ll have little say on future features or updates.

Lift and shift

Simply put, the “lift and shift” method can also be described as another way of saying that an app will move to the cloud. It is a common mistake for companies to categorize their legacy application modernizations under this heading, as it genuinely does not modernize anything. The “rehost” and “replatform” categories above fall under the “lift and shift” label.

The first step in making lift and shift really work is to make sure that the application, which previously operated in the on-premises data center, still has access to the same data and documents once it is in the cloud. You can successfully lift and shift workloads from the data center to the cloud if the access to shared folders remains the same.

Suppose a company did not thoroughly examine its apps before making the “lift and shift” decision, but it still adopted this approach. In that case, it will oversimplify modernization’s goals and merely move technical debt to the cloud without achieving any substantial business benefits.

It’s good to know that you don’t have to make the migration strategy decision alone. Companies can modernize their applications with the most efficient migration strategy thanks to technology. Check out the following section to learn how.

Partnering Strategically to Make Application Modernization Happen

Migration strategies can be complex and diverse, as you may have noticed. Determining which one is the best, implementing it, and preventing risks is not a simple process. However, you can choose a strategic partner to achieve the best results.

vFunction is at the forefront of cloud and application migration. Its goal is to assist leading companies globally in accelerating their journey toward cloud-native architecture and gaining a competitive edge. With a factory model purpose-built for cloud-native modernization, the solution removes the time, risk, and cost constraints associated with manually updating business applications.

Due to its unique ability to automatically modernize complex legacy Java applications, vFunction application modernization transforms complex monolithic apps into microservices.

Through our solutions, software companies can become faster, more productive, and truly digitally transformed. Contact us if you want to see how we can convert your legacy application to a modern, high-performance, scalable, and authentic cloud-native architecture. Request a demo today.

The vFunction platform transforms monolithic apps into microservices automatically, efficiently, and rapidly. It is a repeatable, automated factory model built especially for scalable cloud-native modernization. Designed to provide a fast, accurate and efficient approach to extracting and creating microservices, vFunction lets you get into modern modernization.