Cover image showing ow to upgrade legacy applications

Legacy applications pose multiple problems for data-driven organizations like yours. Outdated software might no longer receive support and maintenance from its vendor or might not integrate with modern technologies like cloud computing. Still, these applications are essential for day-to-day business tasks, and replacing them could impede productivity and profitability. Upgrading legacy applications— instead of substituting them—can save costs and increase flexibility, scalability, and security. 

There are various ways to upgrade a legacy application. The approach you take to modernization depends on your budget and business initiatives. Learn more about this topic below and drive digital transformation in your organization. 

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Why Should You Upgrade a Legacy Application?

You might want to modernize a legacy application in the following scenarios:

  • Your current application can’t interact with newer software, making it difficult to improve digital transformation.
  • Your application can’t integrate with digital analytical tools, making it difficult to identify patterns and trends in data and improve decision-making. 
  • Your application is still functional but doesn’t provide any scalability benefits, making it difficult to grow your business.
  • Your application no longer receives support and maintenance from its vendor, increasing the risk of data security issues.

Upgrading old systems can provide your organization with various benefits:

  • Save money spent on maintaining legacy applications. After modernizing an application, the software might be more functional and experience less downtime. 
  • Improve data governance in your organization. A legacy application might not receive support and maintenance from its vendor, putting sensitive data at risk. That could violate data governance legislation such as GDPR, CCPA, and HIPAA and result in expensive penalties that your business can’t afford. 
  • Reduce data silos that exist in your organization. After upgrading your old software, you can better integrate data between departments and improve business processes. 
  • Enhance data security. Existing systems no longer maintained by vendors won’t receive the latest security updates and patches, making data more vulnerable to breaches and other cybersecurity events. You can prevent data from ending up in the wrong hands, jeopardizing your business reputation. 
  • Reduce downtime. An old software tool might experience outages because it’s no longer compatible with physical servers and other infrastructure. This downtime could make it challenging to execute business processes and impact customer experiences.  

Read more: Legacy System Modernization

Plan Your App Modernization Project

Successfully upgrading a legacy app won’t happen overnight. The modernization process requires planning and persistence and might take several months, depending on the app that needs updating. Here are some tips for modernizing legacy apps:

  • Decide what you want to get out of modernization. Do you want to upgrade an app to comply with a data governance framework? Do you want to add new features to a software tool? Do you want a tool to run faster? Do you want to improve the user experience? Set goals for your modernization project before you start. 
  • Create milestones for your project. How long do you think modernization will take? Do you need to complete the process by a particular date—before the holiday season when sales increase, for example? Setting important dates will help you visualize your modernization project and allow you to plan accordingly. 
  • Create a budget for modernization. Upgrading legacy apps can be expensive depending on the approach (more on that below). Decide how much you want to spend on your project and stick to your budget as much as possible. 
  • Come up with a plan B if modernization fails. If the worst-case scenario happens, can you continue to use your legacy app for a little longer? Or does your business require new solutions right now?
  • Think about the complexities associated with your project. For example, will your modernization approach require lots of coding or experience in programming languages? Will you need to enlist the services of outside developers to make modernization happen? How much will that cost your organization?

Choose a Modernization Approach 

Once you’ve made the decision to upgrade a legacy application, you need to decide on an approach to modernization. You can’t upgrade all applications using the methods below; modernization depends on your software tool’s age and scalability capabilities. 


Encapsulation is a modernization approach that extends the functionality of your current application by providing additional features as services through an API. This model develops the application’s interface and essentially recycles different software components. The result? You can facilitate new business processes without affecting a mainframe application.

Because encapsulation only develops the legacy application’s interface, this approach doesn’t upgrade the software’s internal components. However, encapsulation lets you optimize the app’s functionality and get more value from it when executing business tasks. 


The rehosting approach to modernization involves transferring a mainframe application to physical or cloud infrastructure without changing the application’s code or functions. For example, you can move an existing application to the cloud and gain scalability and data storage benefits. The app will perform in the same way after the rehosting process.  


Refactoring means changing and updating the code in an existing application without causing changes to the application’s behavior. That can improve functionality without needing to retrain users on how to interact with the application. 


Rearchitecting involves moving an application to a new infrastructure by changing its code. This method can improve the functionality of a legacy application. 


Rebuilding or redesigning an application from scratch requires more work than other modernization techniques. However, this approach can add new features and functions to a legacy application, fulfilling your business objectives.

API Integration

Another way to modernize legacy applications is through a REST API, which helps you deal with outdated software with data like master client data. Alternatively, you can use the code in your existing application to create a microservice and connect it to an API.

Read more: Legacy Modernization and the Value of Enterprise Systems

Understand the Risks Involved in Modernization

Modernizing legacy applications comes with various risks depending on the method used. 

Data Loss

Modernization techniques like rearchitecting involve migrating data from a legacy app to a new infrastructure. That can pose challenges such as data loss, which can happen when an organization doesn’t properly execute a migration project or makes mistakes when implementing a particular technique. Data loss can spell disaster for any organization and can trigger lawsuits from customers and penalties for data governance non-compliance. 


Data modernization might cause downtime when data moves from a legacy application to another location or developers rebuild or rehost a software tool. Downtime can frustrate customers who need access to the data in your software and the employees who rely on an application to complete day-to-day tasks. 

Data Breaches and Cyberattacks

Moving data from an on-premise legacy app to infrastructure like the cloud can increase the risk of data breaches and cybersecurity events. Your organization must use a reputable service provider that values data security as much as you do. 

Modernization Can Be a Time-Consuming Process

Changing or writing new code for a legacy app can take time and resources. Organizations inexperienced in upgrading legacy software can also make mistakes that delay the end date of modernization projects. 

It Can Also Be Expensive

Modernization might involve hiring an outside team to upgrade legacy apps or investing in new technologies. All modernization techniques involve some outlay, so organizations should consider an approach that suits their budget. Also, consider additional maintenance costs when old software has new features and capabilities. Whatever the final cost, modernizing an existing app will likely work out to be less expensive than investing in a new application.

The right REST API management platform can mitigate the above risks and ensure your modernization process runs smoothly. 

Read more: Modernizing Business Technology: Legacy System Modernization Through APIs

Software Modernization Use Cases

An organization uses a legacy application that has served its business needs for over a decade. However, the application’s vendor no longer offers maintenance and security, putting data in the software at risk. The application also doesn’t integrate with data analytics tools, making it difficult to identify patterns and trends in data. 

The organization decides to upgrade the application. It plans a modernization project and sets milestones for the project, which helps employees prepare for the upgrade. The organization chooses the rearchitecting approach to modernization. This approach involves moving the application to a new infrastructure by changing its code. That will improve the functionality of the legacy application and enhance business processes. 

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Final Thoughts

Legacy applications make it difficult to scale, secure, and get value from your business data. When it’s not feasible or affordable to replace these applications, consider a modernization approach that improves performance and productivity in your organization. Upgrading legacy apps can carry risks, but choosing the correct method will maximize your current software tools and make it easier to complete day-to-day jobs.  

DreamFactory can help you update your legacy applications through encapsulation, refactoring, rearchitecting, and other modernization techniques. It can also reduce the risks associated with modernizing legacy apps. Start your 14-day free trial now!