How to Undertake Legacy Application Modernization: A step by step approach

Steps to Modernize Legacy Applications

In 2017, Global businesses spent $3.5 trillion only on IT, of which $1.3 trillion was spent on enterprise software & IT services. Companies spent a lot of funds to maintain an existing enterprise application running the business. It was the only way of preserving the status quo.

However, in 2021, things have changed, and legacy applications aim to have a modern infrastructure, including the cloud and containers, holding great promise for companies wanting to reduce their IT expenditure and convert savings into a competitive advantage. Of course, app modernization makes sense if done right.

What is Legacy Application Modernization?

Legacy application modernization is a unique process to take existing legacy applications and modernize the platform infrastructure, its internal architecture, and features. This discussion mainly involves applying modernization today, which focuses on monolithic, on-premise applications and is maintained with the help of the waterfall development process. It also considers how the applications are brought into the cloud architecture plus release patterns like microservices DevOps.

There are several benefits of introducing an application modernization strategy, such as the improved efficiency of new feature delivery, exposed functionalities of existing application consumed through API and other services, and re-platform application from its current on-premise position to the cloud for application scaling and performance, along with long-term data center and IT strategy.

However, there may be many challenges with app modernization. Typically, it comes down to complexity and cost. Migrating an on-premise application to the cloud involves a lot of planning to ensure a more significant ROI. Otherwise, it is just moving for the sake of it. Conversely, applications might even benefit meaningfully through re-architecturing and re-platforming, but they may be heavily connected to the existing infrastructure and systems, and complexities might outweigh its upside.

The key to a successful app modernization is to strategize and pick the essentials like speed, performance, cloud, scale, feature development, etc. Anything that can help an application increase ROI and improve overall customer experience is excellent.

Why Should You Modernize Legacy Systems?

Legacy applications, also known as monolithic applications, have two innate characteristics making them ideal for modernization – i) they are tough to update, and ii) they are complex as well as costly to scale.

Monolithic apps have been difficult to update due to architectural reasons. Since all the applications ship together, things become difficult and expensive to add features due to overhead complexities and integration challenges.

They are also costly and difficult to scale due to various reasons. If even an app’s single component is experiencing load and/or performance challenges, it becomes compulsory to scale up an app to serve only the demanding lone component. The approach is the result of substantial wasted compute.

By implementing an application modernization strategy, you can take an app to a microservice architecture with smaller and loosely coupled components that may be scaled and deployed independently of each other. Although there are some challenges, the approach is the route to core value in app modernization.

Reasons to Modernize Legacy Software

Looking for reasons to modernize you Legacy Software?

Application Assessment before Modernization

The best application modernization strategy suggests that it is imperative to go through an application assessment. Taking inventory is the first step to know where to begin and how to go about this challenging transformation.

Once you are prepared with the list, start putting things in place to increase the value of modernization. You may also consider potential values as to how crucial the specific application is to your customer’s experience and the organization’s future.

Applications that fall into the top categories are the ones that hold high value, low effort with the least troublesome aspects to begin the modernization project.

However, the trickiest decision involves the high-value apps that make movement difficult. For such apps, it need not be an all-in-all strategy on the first day. These approaches to app modernization reduce costs and risks while moving the portfolio in the right direction.

Key Technologies Used For Application Modernization

There are several technological components in modernization, which include:

1. Serverless Computing: Cloud-based models execute functions in the cloud, off-the premise, do not eradicate server requirements, despite its name. The technology outsources the software code to a cloud service provider that runs it based on respective requests.

2. Kubernetes and Containers: These tools allow developers to build consistent and scalable applications across different environments. Having such flexibility offers multiple benefits to an organization migrating to the cloud.

3. Refactor Monolith into Microservices: Monolithic applications are challenging to update due to architectural reasons. As the components are packed together, it is often difficult and expensive to add new features due to integration complexities. Moreover, scaling monolithic applications can be costly. Scaling an entire application could present many challenges and might even lead to complications. Alternatively, companies are trying to transform monolithic applications into relevant microservices.

How to Develop a Strong Application Modernization Strategy

The global size of application modernization services is predicted to grow from $11.4 billion in 2020 to $24.8 billion by 2025, at a CAGR of 16.8%.

Key factors that drive application modernization are cloud services and SOA (Service Oriented Architecture), growing focus transformation and modernizing existing legacy systems, and rising demand for current infrastructure for business continuity.

Here are the five integral steps to carry out:

#1: List Mission-Critical Applications

Firstly, it is critical to identify high-value assets. Consider how those applications could benefit from improved performance, scalability, reliability, and security.

Make sure you are clear about the functions of the application, the problem areas, and the opportunities. Consider maintenance costs and their modernization benefits. From that point, dig deep into the applications specifics like how services are delivered, who all can leverage it, and its capabilities and limitations. Deep data is highly beneficial for such insights. This data is also equally crucial to agencies, but they must derive data from stakeholders as well.

With all this data, leaders are equipped to make precise decisions about the applications and invest in this initiative, thus linking modernization goals to the priorities of the mission outcomes.

#2: Check Resource Inventory

Application modernization involves technical as well as cultural challenges. A successful strategy must look into both.

To assist transformation efforts, companies must identify leaders possessing granular command over applications and interdependence, including the type of application, connected sources like database-network-storage and others, and maintenance.

Skillsets in the team should be a priority. Proper understanding of development methods and IT support is pivotal.

Developing Application Modernization Strategy

#3: Find the Right Modernization Approach

Response range from adding features to existing architecture, ensuring better alignments with end-user needs, reconstructing and retooling the infrastructure – anything can be involved. With containers, modern application stacks, the cloud, and microservices, it is easier to build, deploy and manage government applications and even scale them to meet the demand.

#4: Reachitect & Refactor or Rewrite

Rebuilding applications is challenging. It involves rewriting various portions of an application right from scratch by preserving its original specifications and scope. If any organization changes the original software code to access the new architecture of an application with desired capabilities, it is known as rearchitect.

If this process restructures and improves the existing code without altering external behavior, it is known as refactoring.

While the rearchitect approach has moderate risks involved with costs, it produces positive results. For instance, contemporary COBOL technology includes different features primarily intended to ease and accelerate alternations in the original application. As a result, rapid changes are expected to the COBOL source code.

#5: Re-platform or Rehost

A survey found that over 55% of the retail enterprise businesses still relied on the mainframe to complete business transactions. Mainframe modernization, or moving off the mainframe, may require significant changes to the source code or application to migrate it to another runtime platform. Just like moving an app to the cloud, the primary concern is data security. In the case of mainframe modernization, it may be required to entrust the organization’s data security to a migration specialist.

Rehosting means moving an application to a new infrastructure, be it physical or the cloud, without making any alterations to the source code or even changing the features.

Modernize Legacy Applications

Modernize your Legacy Application with Radixweb’s Expert Services.


Modernizing an application is the first and foremost step to discover different possibilities or opportunities for investment like moving data into a data lake, leveraging AI and/or machine learning tools, and other such modern tactics. Legacy application modernization offers endless opportunities, whether it is mainframe modernization or simply moving to the cloud. It’s high time that businesses leave legacy applications far behind and move forward towards an advanced and modern future. Application modernization services from a trusted partner can be an excellent choice to look ahead from this point onwards.

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Pratik Mistry is a rare mix of technologist and vice president of sales at Radixweb. His passion lies is in helping companies to grow revenues by delivering top notch software development services and build value-based partnerships. When not driving high-impact go to market strategies, Pratik loves to try new cuisines and going to the movies.