Strategies for the Application Modernization of Legacy Systems 

When hearing the words “legacy system”, what immediately comes to mind is an application that has been developed over years or even decades and uses an old-school tech stack. However, today, in the rapidly evolving world of technology, any system can soon become a “legacy” one. Its poor performance and low resistance to cyberattacks without the right security patches can quickly make monitoring and maintenance a nightmare. In this guide, you will find proven modernization approaches for the digital transformation of enterprise legacy systems.  

Why is Application Modernization Essential for Legacy Systems? 

When a system is referred to as a legacy system, it can mean many different things: 

• it no longer meets architectural standards, 
• it uses outdated technologies (old programming languages, tools or platforms),  
• it has no support for certain plug-ins, 
• maintenance and fixing errors require a lot of effort, 
• its development is blocked because of the legacy code, 
• a lack of up-to-date documentation, 
• compatibility issues between older systems and newer technologies. 

Modernizing such systems is challenging, as they are often key enterprise applications. Reviving them is perceived as problematic because of their complexity. As the saying goes: “if it ain’t broke, don’t fix it!”  

This would be true, but not in an era where “just working” would be enough. Modern systems are scalable, more load-bearing, and simply faster. You can’t expect to outdo the competition with a system that does only what it’s supposed to do. 

The Importance of modernization in legacy systems 

The purpose of the modernization journey undertaken by so many companies is not to “get rid” of a legacy system – often it’s quite the opposite. The “why” behind the scenes is to maintain application functionality and improve its performance with newer technologies – either by migrating to the cloud platform, code refactoring, or changing its architecture.  

Which technologies are considered legacy ones?  

In the case of legacy code, the issue is quite clear: it’s about obsolete or unnecessary code that doesn’t fit in with new technological developments. All right, but what do we mean when we say “legacy technologies”? When does technology become a legacy? Does “legacy” refer to the technology stack itself, or do we need to understand it more broadly?  

In the world of technology, legacy technology may refer to different areas: 

• Older programming languages such as Cobol (Common Business Oriented Language), used in business and finance applications, or Visual Basic, especially popular in the 1990s and 2000s, succeeded by the .NET framework, or Perl.  
• Architecture styles, including SOA (Service-Oriented Architecture), Client–Server Architecture, and monolithic architectures. 
• Software development approaches can also be considered legacy ones. For many, the traditional waterfall approach is an outdated approach, contrary to Agile iterative frameworks like Scrum, Kanban, or DevOps, which bring greater flexibility and a sense of fresh air to the projects.  
  

How to identify legacy software in your company 

To effectively recognize legacy technologies in your company, a number of key questions must first be analyzed. At the outset, in order to start the discussion on categorizing legacy systems, they must first be identified. 
 
Key questions should be asked, such as: 

• Is the software based on outdated technology? 
• Is it incompatible with current systems? 
• Is the source code or documentation no longer available for this system? 

If we have correctly identified that at least one of your applications is considered ‘legacy’, we recommend establishing additional facts: 

• Do they pose a risk to your organization? 
• How much does this application cost you annually in maintenance fees? 
• How many changes are being implemented and how much does it cost per year? 

The steps indicated will allow you to better understand which systems require attention and management action. The effective identification of legacy technology will enable you to make more informed decisions relating to IT infrastructure maintenance and long-term business strategies. 

Benefits of Application Modernization for Legacy Applications 

It’s highly likely that software developed for over 5 years won’t meet your growing needs and recurring issues will impact its performance. Here are the main advantages of modernizing your app:  

• Cutting costs – by eliminating technical debt. Legacy systems tend to be very expensive to maintain. Much of this cost comes from managing legacy code and the growing number of support tickets. Diagnosing problems takes hours or even days, and few team members know how to work with an older system. 
• Improved performance and speed – poor performance is an important reason to implement more modern solutions. Through the modernization process (including application development) you can significantly increase the speed and resilience of your systems. 
• Enhanced security – security vulnerabilities are not just a roadblock to modernization. Only after modernization, with new protocols and authentication methods, will you meet security standards for systems and applications.  
• Business Flexibility – legacy systems limit a company’s ability to create new features and services. Moving legacy software to the cloud by rolling out microservices and containerization also gives your organization the ability to add new features and functionalities. 

Key Technologies for Application Modernization 

Two aspects in particular are worth noting. Firstly, containers have become a key technology in application modernization due to their capability to package and isolate applications with their dependencies. 

The second such aspect is hybrid cloud solutions. Legacy systems can often be complex and difficult to upgrade, especially if tied to on-premises infrastructure. A hybrid cloud offers a way to modernize legacy systems by integrating them with cloud services while still maintaining some components on-premises.  

Understanding the Role of Containers in Modernization 

Application modernization often tends toward having secure and highly available applications. Containerization is an excellent response to the need to build scalable, efficient, and fail-safe systems that will run on multiple platforms, and, of course, in the cloud. Containers that bring together individual microservices positively impact application reliability. 

The advantages include speed, better integration, and improved application lifecycle management. In an era of resource optimization, companies are also looking to modernize infrastructure by reducing resources. Here, too, containers will do well, as they are more efficient than virtual machines, which in turn require an evolved operating system and need to run their own resources.  

Exploring Hybrid Cloud Solutions for Legacy System Upgrades 

Cloud migration is not the only way to modernize legacy apps. Many companies opt for a hybrid cloud, which means benefiting from infrastructure that is a blend of private and public cloud services. 

Such a solution is flexible and extremely popular. As many as 70% of companies are utilizing it today, according to Flexera’s State of the Cloud Report. Employing hybrid cloud solutions for legacy system upgrades involves the deployment of existing applications from on-premises environments to public clouds such as Microsoft Azure, Google Cloud, or AWS Cloud. This type of application modernization process is vitally important for all businesses looking to enhance productivity and meet their changing business needs.  

Automation in Legacy Application Modernization 

One key aspect of the application modernization process is automation, which significantly expedites the transition from a legacy application to a cutting-edge business application. In a fast-paced IT environment, companies aim for more releases and better software quality, and the ideal way to do this is to implement DevOps automation tools.  

Such solutions also include predictive analytics capabilities, so the system is monitored, optimized, and maintained in real time. By automating testing, code refactoring, and integration, organizations not only deploy software faster but also gain business value quicker when compared to more traditional methods.  

Best Practices for Successful Application Modernization 

An application modernization strategy is essential for organizations looking to stay competitive but also not wanting to waste their budget on maintaining legacy applications. With legacy modernization becoming the way to go, companies must develop a comprehensive approach to updating their legacy systems.  

Implementing Cloud-Native Strategies for App Modernization 

As cloud solutions have gained popularity, the role of cloud-specific functionalities allowing you to use their full potential has increased. Such cloud-native solutions include microservices, containerization, API integrators, or serverless solutions – it is difficult to imagine any modern application without them.  

• Also read: Cloud-native applications: all you need to know 

Accelerating Application Delivery through Modernization Efforts 

According to research, the average application modernization process takes 16 months. We cannot deny it: this is a lengthy and laborious undertaking. Fortunately, application modernization services can be accelerated without compromising the quality of solutions. And here again, let’s turn back to the DevOps model, which in the world of state-of-the-art application development is no longer an innovation but the standard. 

The DevOps model works well, especially in projects in which a company decides to modernize a system and then hand it over for maintenance to external experts (e.g., in a nearshoring model).  

Application Modernization Patterns and Strategies 

If you are planning to modernize your monolithic application, migrate to a cloud environment, or simply modernize the software, familiarize yourself with the most effective strategies, also known as the 7 Rs:  

1. Rehosting  
   This approach is also known as “lift and shift” and involves moving the existing infrastructure to a cloud platform as it is. 
    
   Advantages: 
   Such a digital transformation strategy is popular – it comes at a low cost and effort. You don’t need to invest in cloud-native solutions or change the application code, and can still enjoy the same functionalities in a relatively short time. 
    
   Disadvantages:  
   You face the limitations of not using native solutions (such as containers and serverless computing). Also, you are moving the entire application along with its issues and performance limitations.  

2. Refactoring 
   If you want to use a Platform-as-a-Service solution, application refactoring will be an option for you. After application refactoring, you will gain access to cloud-first solutions. 
    
   Advantages:  
   After refactoring, you will benefit from better scalability. You will gain permanent settlements – billing based on resource usage. You can take advantage of the many opportunities provided by cloud-native solutions.  
   
   Disadvantages:  
   Due to code changes, refactoring will require the allocation of more resources and time than in the case of “ordinary rehosting”.

3. Rearchitecting  
   If a legacy application was designed in the old architecture style, you will need to make changes to the application architecture as part of the modernization. Bear in mind that this is a large-scale modernization project.  
    
   Advantages: 
   With modern architecture, you can gain entirely new application performance capabilities and scalability, plus enhanced security. For example, using small components, that is, microservices, instead of one monolithic application allows you to make your application more fail–safe and resilient. It’s also an opportunity to leverage DevOps practices and application modernization tools. 
    
   Disadvantages:  
   Working on the original application architecture requires an appropriate strategy, so any undertaking must be preceded by a solid business analysis. If you are pressured by time, you will have to wait patiently for the results.  

4. Rebuilding 
   When your business needs change significantly, or when the technologies used differ significantly from the latest trends, you may need to rebuild the application, either entirely or partially.  
    
   Advantages:  
   New technologies will take the constraints of dealing with legacy code off developers’ shoulders, allowing for faster application development. You can add new functionalities and rethink existing ones. Furthermore, new technologies attract programmers who want to work with the latest possible stack.  
    
   Disadvantages:  
   Application rebuilding will involve additional work (e.g., database migration) and a greater potential risk that not all functionalities will work as expected. It is the most time-consuming and costly option.   
    
   You may encounter difficulties in finding experts with the right seniority for the application rebuilding project. In such a situation, it is worth considering external support.  

5. Replatforming 
   This strategy is also known as “lift and reshape”. Moving the application to the cloud, while taking optimization work into account – with this approach you can take advantage of cloud-native capabilities relatively quickly.  
   
   Advantages:  
   No changes need to be made to the application code, and during the migration process, the application is available all the time. This saves time and money while keeping the application running.  
   
   Disadvantages:  
   The process should be well -thought -out to avoid time-consuming additional work (and thus expanding the scope of the project). 

6. Replacing/retiring 
   None of the above app modernization strategies may turn out to be suitable for your project.  
    
   The decision to replace a legacy application, even a business-critical one, is not easy to make, especially if you have invested a great deal of time and money in developing your custom business solution. 
    
   Advantages:   
   There are many Software-as-a-Service solutions available today that can have similar functionality to your application and will not generate maintenance costs. It’s a strategy that is easy and quick to implement and comes with the predictable fees, upgrades, and security of the solution provided by the vendor.   
    
   Disadvantages:  
   When opting for a SaaS solution or any other commercially available application, you have limited influence over its design or development. You also have to consider the legal aspects of data processing and available options for integrating the application with other systems. 

7. Retaining 
   If, for security reasons or existing dependencies, upgrade work cannot be planned, companies opt to “leave it as is.” This does not mean, however, that no works are planned. They are simply postponed until a more favorable time – when the company has met security or compliance standards.  
    
   Advantages:   
   Such a strategy provides an opportunity to evaluate the process and properly prepare for modernization, and then upgrade an application when modernization is in a position to bring business value. 
    
   Disadvantages:  
   You still have to deal with the problems of the legacy application for some time and bear the costs of its maintenance. The longer an upgrade is postponed, the longer a company fails to benefit from the potential of cloud-native solutions. 

Developing a Comprehensive Application Modernization Roadmap 

Each approach to application modernization will affect areas such as the budget, application availability, resource commitment, scope of work, or risk. Choosing the right strategy will help you avoid unnecessary effort and cost. There are tools available to estimate your needs, such as Gartner guides, which will walk you through the world of modernization. 

You can also take advantage of Application Managed Services that usually offer flexible development and maintenance models.  

The process of evaluating the modernization of applications 

To evaluate the modernization process of applications at Inetum Poland, we follow a structured approach considering various factors such as complexity, risk, impact, workload, architecture, cost, operations, and security. Below is a description of how we go through the evaluation process: 

• Confirm the feasibility of modernization and define the problem. Before proceeding with any modernization effort, we ensure that the possibility of modernizing a legacy application is confirmed, and the problem is clearly defined by the customer. 
• Select the modernization approach. We apply seven approaches known as “the 7 Rs”, ranked from lowest to highest in terms of complexity and risk.  
• Consider all factors. We carefully consider factors such as workload, architecture, cost, risk, operations, and security when choosing the modernization approach. The priority given to each factor depends on its importance to our business objectives. 
• Choose the right resources and skills at Inetum Group. In acknowledging that small in-house teams may lack the skills needed to upgrade legacy systems, we understand the importance of adequate resources and the highly skilled experts we have throughout the Inetum group. That’s why having a large team of skilled experts in various technologies helps us to achieve optimal results in the short, medium and long term. 
• Optimize and analyse. We understand that the modernization process is iterative and requires constant optimization. Therefore, we continuously test and optimize application modifications to ensure smooth hosting, software licensing, and connectivity during the transition phase. 

By following this structured evaluation process, we ensure that our modernization efforts are aligned with our business objectives, minimize risks, and maximize the positive impact on our organization. 

Modernizing legacy applications – summary 

Application modernization includes incorporating new features and taking advantage of cloud computing technologies. This modernization can involve transforming a legacy application into a cloud-native application that leverages cloud infrastructure and a managed services model. 

Cloud application modernization is an essential aspect of any application modernization project, sometimes called legacy modernization. This approach to application modernization entails taking an existing application from the existing application portfolio and migrating it to the cloud to reap the numerous benefits of cloud technology. A modernized application is a better experience both for you and the programmers maintaining the project. 

Streamline Your Application Maintenance

Leszek Jaros, our Head of Telco and AMS Practice, is here to help you navigate the complexities of Application Maintenance Services. Book a consultation to boost your application's efficiency

Schedule a meeting