How to Modernize Legacy Applications


Julia Sakovich , Author at Geomotiv
Published: Jul 22, 2021

Digitalization is moving forward. Today, it is hard to imagine any modern business without software solutions for internal use or interaction with clients. However, the issue is that today many companies are still using their solutions built 10, 15, or even 20 years ago. Given the pace of technological development, it is quite natural to suppose that these apps simply do not meet the current industry standards and can’t allow companies to meet their business goals. But can we say that launching a new application instead of the existing one is the only option available? Definitely not. And that is when legacy application modernization enters the game.

Let’s dive deeper into this topic and analyze what new opportunities it can offer to businesses.

What is Legacy Application, and What is Legacy Modernization?

There are no exact timeframes that can help you understand whether this or that app can be moved to the group called “legacy” or not. However, there are some other indicators. Any outdated app that does not meet your business requirements can be referred to this category.

The process of changing your legacy software products with a view of increasing their efficiency, performance, and capacities in satisfying the ongoing needs of the organization is known as modernization.

It can deal with moving on-premises applications to a cloud platform or a new architecture. For example, it is possible to change a sizeable monolithic software to microservices. The app can be brought to a more efficient platform, or its functionality can be expanded with new features. Various options can be chosen depending on your expectations and resources.

It is interesting to note that in 2020, the value of the application modernization market was around $11 billion, and it is expected that this figure will reach $24.8 billion already by 2025. At the same time, which is quite logical, the revenue of the global app modernization tools market is growing as well. Thus, there is a chance that by 2027, it will hit $36.86 billion.

Application Modernization Tools Market Revenue Worldwide from 2018 to 2027

But why can we observe such positive tendencies in the sector of app modernization? The answer is quite simple. First, the number of applications that do not meet the modern requirements anymore is increasing. And secondly, modernization has a broad scope of benefits for businesses.

Why Modernize Legacy Systems: Key Reasons

It’s crucial to understand that there aren’t any one-fits-all solutions. Instead, each particular case requires deep preliminary analysis and consideration of different possible variants, including the most radical one - replacing the legacy application with a new product developed from scratch.

However, if legacy modernization is feasible in your case, let’s have a look at the most important benefits of this approach:

  1. Reduced operational costs. According to some studies, modernization can help you decrease costs by up to 13-15%.
  2. Higher performance and lower risks. Modernized legacy software demonstrates better productivity and performance thanks to faster data processing.
  3. Enhanced security. With the flow of time, the security standards change, and it is evident that the software built 10-15 years ago does not meet the modern requirements in this field. Modernization will ensure the better security of your app by the latest innovations. 
  4. Greater scalability and flexibility. With newer technologies, your application will be more stable, allowing you to update and expand it based on your needs.
  5. Improved customer satisfaction. Modernized software will provide you with more UI/UX design possibilities that play a vital role in making your users happy.

The main thing that we want to highlight is that modernization is an excellent way to make your obsolete software meet modern industry standards and, as a result, to let your business hit new goals amid total digitalization.

Geomotiv’s team successfully migrated a part of the client’s ad server to the cloud to ensure scalability, manageability, and fault tolerance.

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Legacy System Modernization Strategies

As we’ve already mentioned, there are several approaches to the modernization of legacy code. And the choice will depend on numerous factors. Just to name a few, their list includes the type of your software, the used technology and deployment platform, the current performance and functionality of your app, your expansion plans. But do not worry. Come to us with a request to modernize a legacy application. We help you to define the most suitable legacy modernization approach in your case.

So, the most popular modernization strategies are:

  • Legacy modernization. Modernization may include different tasks and processes, from simple upgrades or enhancements of particular components within the existing infrastructure to total re-engineering. The exact migration plan is elaborated after the evaluation of your software and your business goals.
  • Legacy application migration. This approach presupposes moving your app to new technology, platform, or environment without affecting its architecture and business logic. One of the most famous examples of this approach is your on-premises apps with all their data and infrastructure to the cloud migration. With the correctly chosen strategy for migrating your software, you can ensure its better efficiency and continuity.
  • Development from scratch. In some cases, it is sensible to replace legacy systems with newly built ones. This approach is usually applied either when there isn’t any possibility to reuse the legacy business logic or when it is costly to modernize legacy apps.

Legacy Application Modernization Techniques

When it comes to choosing how to modernize legacy systems, we usually consider the variants from the list provided below. However, the complexity of these techniques and the time needed for their realization significantly differ. Our experts always conduct a preliminary evaluation of their feasibility before offering a possible solution to the client.

  • Encapsulation.  This methodology allows extending and leveraging the app features thanks to making its functions and data available via an API as services. It becomes possible thanks to encapsulating the processes and data of the app. As the software code remains in the same environment, the risks and the costs related to this migration are relatively low.
  • Rehosting. If you opt for this method, the app component is redeployed to another infrastructure. Rehosting helps to ensure timely UI/UX updates as well as a performance optimization. At the same time, the functions, features, and code of the app are not modified.
  • Replatforming. Migration of your software to a more efficient business platform allows leaving the existing code structure, business logic, and functionality unchanged. The amendments introduced to the code are explained by the necessity to ensure the smooth functioning of all the business components in a new environment.
  • Refactoring. When this approach is chosen, the existing code will be restructured and optimized while its external behavior is not changed. This method is a suitable variant when it is necessary to remove technical debt and improve the structure and the features. As a rule, the introduced updates do not influence the business logic of your app.
  • Rearchitecting. This approach involves moving your app to a new architecture which causes the necessity to transform the existing code. As a result, the modernized app will have significantly more comprehensive capabilities.  Rearchitecting is associated with higher risks and costs than, for example, encapsulation.
  • Rebuilding (or redesigning). It includes the creation of a particular component (or components) of the app from scratch. However, their scopes and specifications will remain the same. As a rule, this method will be a good idea in those cases when you need to expand your application with new functionality and features.
  • Replacing. Sometimes it may happen that retiring the obsolete components and moving to new ones that can meet the up-to-date needs of your business and the latest requirements of the industry is the best option. Changes in business logic, reengineering, and customization of some parts can also be among the entire process elements. This method, as a rule, is the most expensive one on this list. However, the results are worth all the investments.

Share your pains with us and we help you breathe in a new life into your obsolete software.

Our Expertise in Legacy Code Migration and Modernization Projects

It is time to share Geomotiv’s experience with legacy software of various types. As we’ve been delivering custom solutions for 10+ years, we’ve accumulated rich practical experience and comprehensive theoretical knowledge of the latest trends in software development. Hopefully, our stories can help you see the advantages of the approach we went with and decide whether it suits your next project.

RTB Platform Logging System Optimization

HIRO Media, an industry-leading video AdTech service provider, turned to Geomotiv to prepare their RTB system for the increased load.

Our team conducted a thorough analysis of the original system to detect possible issues. We aimed to find a set of technology limitations that could affect the platform’s performance under increasing load. Geomotiv’s specialists revealed that the existing solution utilized a MySQL database to aggregate, read, and forward raw event data simultaneously. 

Having found this limitation, our developers started to compile a list of possible solutions, tested them, and picked the most optimal solution. This option responded to the client’s requirements, which gave us the go-ahead for its implementation and deployment.


  • Decreased SQL query execution time;
  • Readiness for a 30% company’s growth.

RTB Platform Migration to Hadoop

Our team was involved in another project for the client mentioned above. To meet the up-to-date needs of their company and optimize growing spend it was necessary to migrate the system from the Microsoft SQL Server to Hadoop.

First, we collected the system’s inner workings and decomposed the ETL process between input and output servers. As our next step, the team explored pipeline operations on both high and low levels. That gave us solid ground to kickstart the migration process. We got down to reengineering the data processing layer from the ground up to make it ready for the Hadoop ecosystem.


  • Reduced TCO of the system;
  • Greater scalability;
  • Decreased batch processing time.

Legacy Platform Migration to AWS

Hiro Media turned to Geomotiv once again to move their existing ad network service to a new environment. The platform contained a lot of legacy code and was difficult to expand to meet current business goals. Our team proposed the client migrate parts of their ad server to the public cloud, namely, AWS.

For that, we refactored and optimized the existing code and implemented additional components without affecting the platform’s business logic. Our team transferred the incoming raw event data to the Amazon S3 file server and transformed obtained values into a Redshift database.


  • Enhanced scalability;
  • Streamlined data recording and processing.

Summing Up

We hope our article helped you understand the essence of legacy software modernization.

If you are looking for a reliable technological partner to care for your legacy applications, our expert team is ready to help! Leave your inquiry online, and our experts will contact you as soon as possible.



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