We uses cookies to ensure that we give you the best experience on our website. Privacy Policy Ok, Got it

Art of Legacy Application Modernization: A Detailed Guide

Art of Legacy Application Modernization: A Complete Guide
blog-author Robert Team Leader
Richa Richa Technical Content Writer

“Compulsive modernization is the insatiable desire to change and grow.”

–  Samuel Wilson

An organization that uses outdated software, technology, or a method or language even after it has been replaced by more modern technology is said to be using a legacy system.

These systems are difficult to combine with other systems and are incompatible with more recent hardware or software platforms. That’s why future-proofing your systems with legacy application modernization strategies is needed.

Application Modernization Services Market

Application Modernization Services Market

Image Source

A survey conducted by Adobe and G2 found that 52% of workers are unhappy in their current positions as a result of mismatched or missing software. 32% of workers have changed jobs because they felt that their employer’s use of technology was impeding their capacity to perform well.

The main goal of modernizing legacy programs is to solve all of their problems, including cost and employee and customer experience. You’ll face typical issues and risks caused by out-of-date technology as your systems and apps begin to deteriorate and become legacy systems, such as:

  • Difficult to keep up.
  • Bloated code.
  • Hacked integrations.
  • Integration with third parties is not supported.
  • Performance problems and slow load times.
  • Risks to compliance and security threats.
  • Inability to keep up with new tasks and workflows.
  • Poor customer experience.

But what can we anticipate from legacy system modernization? This is the most important thing your company needs to know before implementing any legacy application modernization strategies. By following a step-by-step approach, businesses stand to gain optimal value from the process.

This blog is a great start for modernizing legacy applications for both professionals and beginners. Without further delay, let’s start from the basics and understand the need, greed, and deed for modernizing your legacy software!

What is Legacy Software?

What is Legacy Software?

Legacy software refers to outdated computer programs or applications that continue to be used despite being built on older technologies. These systems often lack support, updates, or compatibility with modern hardware and software.

Legacy software can pose challenges for organizations, as it may be more susceptible to security vulnerabilities and difficult to integrate with the latest technologies.

Generally speaking, a company still actively uses legacy software systems because they continue to satisfy a valid business need, wholly or partially. In reality, using it is often challenging!

What is Legacy Application Modernization, and Why Go for It?

What is Legacy Application Modernization, and Why Go for It?

The term “legacy application modernization” describes the process of swapping out outdated platforms with more recent cloud apps and solutions. It is the ongoing process of modernizing legacy systems to lower the costs and complexity of the IT environment, improve data consistency, facilitate cross-platform collaboration, and boost process flexibility.

Modernizing old applications may include replacing them with new ones, introducing fresh ideas to enhance existing systems, or switching to a completely different workflow.

It sounds like a difficult effort to replace software and apps that your team has been using for years, maybe even decades, doesn’t it?

However, using outdated technologies can put your company and clients at greater risk of severe IT problems. Updating legacy apps can help solve issues that come with utilizing out-of-date tools, which will positively impact your overall digital workplace. Teams become more effective, expenses and risks are decreased, and consumers and employees have better experiences.

Examples of Popular Legacy Technologies Leveraging Modernization

  • Many popular legacy technologies are modernized using low-code development approaches to enhance efficiency and agility. COBOL, a venerable programming language widely used in legacy systems, is being revitalized through low-code platforms.
  • Another example is the modernization of mainframe systems, such as IBM z/OS applications, using low-code development to boost efficiency.
  • Microfrontend technology is being applied to popular legacy technologies for enhanced modularity and improved user experiences. This enables incremental updates and facilitates independent development of frontend components.
  • Content management systems (CMS) based on older technologies are leveraging microfrontend patterns to break down large, complex systems into more manageable and maintainable parts.

Let’s understand why and when you should look for legacy application modernizing services to convert your old application into a new, robust, and customized solution.

Why Does Your Business Need Legacy Application Modernization Services?

You must choose legacy application modernization strategies for several compelling reasons, addressing challenges posed by outdated systems and unlocking various benefits for organizations. Let’s discuss some major issues that can be solved by modernizing your old application.

Why Does Your Business Need Legacy Application Modernization Services?

  • Increased Competition

Businesses need to adapt to technological advancements to remain competitive. Modernization allows for adopting contemporary design principles, improved usability, and integrating new functionalities, resulting in a better overall user experience.

  • Compliance with Industry Standard

Regulatory and industry standards continually evolve. Legacy systems may struggle to meet these standards, leading to compliance issues. Modernization ensures that web and mobile apps adhere to the latest regulations and industry best practices, reducing legal and regulatory risks.

  • Business Agility

Applications that have been modernized can quickly adapt to shifting client needs, market conditions, and changing business requirements. This agility allows organizations to respond faster to market changes, launch new products or services, and stay ahead of the competition.

  • Integration with New Technologies

Innovation may be hampered by outdated systems’ resistance to modern technology integration. Thanks to modernization, AI, cloud services, IoT devices, and other developing technologies can all be incorporated. This integration promotes competitiveness, creativity, and flexibility in response to shifting market conditions.

  • Poor Performance

Modernized applications can scale to accommodate increasing workloads, ensuring consistent performance as the company grows. Legacy systems often struggle to meet the performance demands of modern business. Modernization involves optimizing code, updating databases, leveraging newer technologies, and improving system performance and scalability.

  • Security Issues

Legacy applications may have vulnerabilities that pose significant security risks. Modernization involves updating security protocols, implementing the latest encryption standards, and addressing potential weaknesses. This ensures a more robust and secure system, protecting sensitive data from evolving cyber threats.

How Does Legacy Application Modernization Help Grow Your Business?

How Does Legacy Application Modernization Help Grow Your Business?

Legacy application modernization services offer numerous benefits to organizations, addressing challenges associated with outdated systems and unlocking new opportunities for growth and efficiency. Here are several key advantages:

  • Enhanced Productivity

Businesses can benefit from modern technologies and the most recent design standards that encourage usability by updating their legacy systems. As a result, applications perform better, can handle heavier workloads, and scale more effectively to meet expanding business demands.

Explore best practices followed by front-end development companies.

  • Cost Saving

Legacy systems can be costly to maintain and support due to outdated infrastructure and specialized skill requirements. Modernization can lead to cost savings by reducing maintenance expenses, improving efficiency, and streamlining resource utilization.

  • Faster Time-to-Market

Modernization often involves adopting agile development practices and tools, reducing development cycles. This faster time-to-market enables organizations to roll out new features and updates more rapidly, staying competitive in dynamic market conditions.

  • Optimize Business Processes

Modernization facilitates easier integration with third-party systems, APIs, and other applications. This interoperability is crucial for organizations aiming to create a seamless and connected digital environment, improving performance.

  • Better User Experience

Legacy systems often have outdated user interfaces and may lack features expected in modern applications. Modernization allows for adopting contemporary design principles, improved usability, and integrating new functionalities, resulting in a better overall user experience.

Key Technologies for Application Modernization

One essential element of application modernization is cloud computing. Teams can more easily share data across tools, applications, and locations with the help of the cloud. Cloud platforms like Google Cloud Platform (GCP), Amazon Web Services (AWS), and Microsoft Azure offer scalable infrastructure, services, and resources.
download Applications can exchange data and communicate with one another thanks to APIs. This way, you can benefit from cloud computing without replacing the current system and effortlessly integrate legacy applications with more recent cloud-based systems.
7602.1513404277 DevOps strongly emphasizes continuous delivery and automation, fostering collaboration between the development and operations teams. As a result, you can update and deploy apps without breaking a sweat and with speed and reliability.
docker Containers are an approach to packing, deploying, and running workloads and applications focused on the cloud. Application management is made simpler when apps move between environments because of the use of containers for cloud software deployment and operation.
Monolithic vs. Microservices 1200x628 Hero img Microservices, such as microfrontend, decompose large, cohesive applications into more manageable, autonomous services that can be independently developed, implemented, and expanded. This architecture makes updates and maintenance easier by increasing flexibility and agility.
Network%20automation%20vs.%20network%20orchestration%20(3) In software development, orchestration is the automation of several container-related operational tasks, such as networking, scaling, and deployment. While orchestration automates several tasks as a process or workflow, automation sets up individual tasks to run independently.
3a3490d01be9bfd1e006ab4a78c39219 3 Low-code and no-code platforms empower organizations to develop applications with minimal hand-coding. These platforms allow both technical and non-technical users to participate in the application development process, accelerating development timelines.
ServerlessComputing Developers can concentrate on writing code instead of maintaining the underlying infrastructure thanks to serverless computing. Platforms that provide functions as a service (FaaS), like AWS Lambda and Azure Functions, enable code to run in response to events without requiring server provisioning or management.

Full-Proof Legacy Application Modernization Strategies

Modernizing a legacy application is a multifaceted process that requires a strategic approach, collaboration across teams, and a focus on business goals. Below are the key steps to guide organizations through the modernization journey:

Full-Proof Legacy Application Modernization Strategies

1. Identify your Legacy IT Architecture and Systems

Modernization initiatives should always originate from a thoroughly recorded business case. Therefore, leading legacy application modernization services first assesses the state of the existing legacy systems and determines the necessity of updating them.

Eight criteria—which can be divided into business and IT drivers—need to be considered when assessing and updating legacy systems.

business and IT drivers—need to be considered when assessing and updating legacy systems.

  • Business side

Consider modernization if a legacy application cannot satisfy the organization’s new or ongoing requirements or needs to be sufficiently flexible and scalable to support the business in achieving its objectives in the coming years.

Business Drivers Reason
Innovation and Features Introduce new features and innovations to meet evolving user expectations and market demands.
Market competitiveness Stay ahead of competitors by offering a more advanced and feature-rich solution.
Agility Increase the organization’s ability to adapt to changing business needs and industry trends.
Compliance Ensure adherence to industry regulations and standards.
  • IT & engineering side

The engineering or IT departments may also contribute to a business case for modernization. Consider modernizing legacy applications if the business is exposed to security or compliance risks, requires expensive maintenance, or is difficult to support.

IT Drivers Reason
Innovation and Features Modernization reduces maintenance costs, leading to better resource utilization and cost efficiency.
Interoperability Modernized systems easily integrate with new technologies and external systems, fostering a more connected IT landscape.
Security Address security vulnerabilities and ensure a more robust and secure application environment.
Compliance Enable scalability to handle increased workloads and accommodate business growth.

2. Assessment of Legacy Application & Plan Your Goals

Now that a business case has been determined, it’s time to evaluate legacy applications formally. This step aims to collect information about the legacy system that will aid the dedicated development team in creating a strategic plan for effectively modernizing the legacy applications.

Assessment and Planning

  • Inventory and Documentation: Begin by creating an inventory of all components and dependencies of the legacy application. Document functionalities, technologies used, and any dependencies on external systems.
  • Business Objectives: Clearly define the business objectives for modernization, such as improving performance, enhancing security, reducing maintenance costs, or meeting compliance requirements.
  • Impact Analysis: Assess the impact of modernization on existing business processes, users, and data. Identify potential risks and challenges.

Set Clear Goals and Prioritize

  • Define Modernization Goals: Establish specific, measurable, and realistic goals for the modernization effort. Prioritize objectives based on business value and impact.
  • Phased Approach: Break down the modernization into manageable phases. Prioritize components based on criticality and potential for quick wins.

3. Inventory your Data and Map them to Business Processes

Upon approval of the business case and clear direction, the next stage is to inventory all of the IT assets, such as databases, systems, applications, and business processes.

By meticulously inventorying data and mapping it to business processes, organizations can mitigate risks associated with data migration, maintain data integrity, and successfully modernize legacy applications while ensuring alignment with business objectives.

What exactly do you need to do?

Data Inventory
  • Identify Data Sources: Document all data sources within the legacy application, including databases, file systems, and external interfaces.
  • Categorize Data Types: Classify data into categories (e.g., customer data, financial records) to understand the nature of information handled by the application.
  • Assess Data Quality: Evaluate the quality of existing data, identifying inconsistencies, redundancies, or inaccuracies.
Mapping to Business Processes
  • Understand Business Processes: Collaborate with business stakeholders to gain a comprehensive understanding of existing business processes supported by the application.
  • Identify Data Dependencies: Map data elements to specific business processes, identifying dependencies and critical data flows.
  • Document Data Relationships: Create data flow diagrams and relationship maps to visualize how data moves through various processes.
Evaluate Data Sensitivity

Assess the sensitivity of data, considering security and compliance requirements. Ensure that the modernized system complies with relevant data protection regulations.

Prioritize Data Migration

Identify critical data for business operations and prioritize its migration. This ensures that essential information is available in the modernized application from the outset.

Note: In certain instances, you might choose not to modernize a legacy application and to leave it in its current state. For instance, you might not want to trust a public cloud provider with highly sensitive data or trade secrets that your application handles. Alternatively, it might be a specialized application that is difficult to re-platform because doing so would be extremely expensive.

4. Consider legacy application modernization strategy options

Gartner has identified seven application modernization options to consider when building and modernizing your digital solutions. These “7 Rs” of legacy application modernization provide a structured approach for organizations to evaluate and decide on the most suitable modernization strategy.

Each “R” represents a different legacy application modernization strategy. The organizations can choose the one that aligns best with their goals and constraints. Here’s a detailed explanation of each:

The 7 R's of Legacy App Modernization Approach

1. Retain

The “Retain” strategy suggests keeping the existing legacy application without significant changes. This is suitable when the application still meets business needs adequately, and the cost and risks associated with modernization outweigh the benefits.

2. Rehost (Lift and Shift)

The “Rehost” strategy involves moving the application to a different environment without making substantial changes to the code. It’s appropriate when the existing infrastructure is outdated, and a quick migration is necessary. Rehosting allows organizations to benefit from modern infrastructure and potentially reduce maintenance costs without altering the application’s core logic.

3. Replatform (Lift and Reshape)

The “Replatform” strategy entails moving the application to a new platform, making minimal code changes. This is suitable when there is a need for infrastructure upgrade, but the application’s architecture is generally sound. It strikes a balance between quick migration and some degree of optimization.

4. Refactor / Revise

The “Refactor” strategy involves restructuring or rewriting parts of the code to enhance performance, maintainability, and scalability. It’s suitable when specific components need improvement or when transitioning to a new technology stack. It’s a middle-ground approach, offering optimization without a complete overhaul.

5. Rearchitect

The “Rearchitect” strategy involves redesigning the entire application, often adopting a new architecture like microservices. This is appropriate when the existing architecture limits innovation, scalability, or maintainability. It aligns with modern development practices and can lead to long-term benefits.

6. Rebuild

The “Rebuild” strategy entails rewriting the application from scratch while retaining its functionality. It’s suitable when the existing codebase is overly complex, and a fresh start is more cost-effective. It requires a significant investment but offers a clean slate for development.

7. Replace

The “Replace” strategy involves adopting a completely new solution to meet business needs. It’s appropriate when the legacy application is no longer viable or when a more modern and feature-rich alternative is available. It can substantially improve efficiency, user experience, and overall competitiveness.

5. Choose the Application Modernization Approach

Choosing the right “R” for legacy application modernization requires a comprehensive assessment of business goals, technical considerations, budget constraints, and risk factors.

By following a systematic decision-making process, involving key stakeholders, and considering the unique context of your enterprise, you can make an informed decision that aligns with your main goals and sets the foundation for a successful modernization initiative.

You can consider factors other than effort and impact when selecting from the above given 7 R’s, such as their:

  • Architecture
  • Cost (modernization and continued operational)
  • Workload
  • Risk
  • Operations
  • Security

6. Build an Application Modernization Implementation Team

Building an effective application modernization implementation team requires assembling diverse professionals with complementary skills. Start by appointing a project manager to oversee the initiative.

Seek a digital transformation agency specializing in re-engineering systems, processes, and technology using different modernization approaches. Choose a development team that uses Agile and DevOps techniques to optimize the time-to-market for your modernization project.

7. Determine Timeline and Success Metrics

It is imperative to test and optimize the modified application iteratively once a project has started to ensure there are no kinks in the software licensing, hosting, or connectivity to other services or databases during the transition.

The complexity of your changes and your chosen modernization strategy will determine how long your modernization process takes. Assemble your timeline with the objectives you wish to accomplish by each date. Also, look into,

If your team is on the course, how will you know?

What increases in productivity do you anticipate?

What signs will let you know if you’re falling short of your objectives?

Evaluating the success of legacy application modernization involves assessing key performance indicators (KPIs) aligned with project goals. Monitor improvements in application performance, responsiveness, and scalability.

Successful modernization should demonstrate enhanced security, streamlined workflows, and overall cost-effectiveness. Regularly review these metrics to ensure ongoing success and adapt strategies as needed to continually optimize the modernized application’s performance and alignment with organizational goals.

Risks Involved in Modernizing Legacy Applications and how to avoid them

Make sure to consider below points while modernizing your old application

Risks Involved in Modernizing Legacy Applications and how to avoid them

  • Business Disruption

Risk: Disruption to business operations during the modernization process.


  • Adopt a phased approach to implementation, allowing for gradual rollouts and minimizing downtime.
  • Develop a robust rollback plan in case of unforeseen issues.
  • Communicate changes effectively to stakeholders.
  • Data Loss or Corruption

Risk: Potential loss or corruption of data during the migration process.


  • Implement comprehensive backup and recovery mechanisms.
  • Conduct thorough data validation, cleansing, and testing before, during, and after migration.
  • Ensure data integrity through checksums and validation routines.
  • Security Vulnerabilities

Risk: Introduction of security vulnerabilities, especially if the legacy system has outdated security protocols.

Mitigation: Update and implement modern security measures, conduct code reviews, and perform penetration testing to identify and address potential weaknesses. Adhere to security best practices throughout the modernization process.

  • Skill Gaps

Risk: Lack of expertise among the existing team in dealing with new technologies.


  • Provide training and upskilling opportunities for the existing team.
  • Consider hiring external experts or partnering with specialized vendors to supplement skill gaps.
  • Foster a culture of continuous learning.
  • Legacy System Dependencies

Risk: Dependencies on other legacy systems or external components that may be challenging to modernize.

Mitigation: Conduct a thorough analysis of dependencies and develop a strategy to address or replace them. Consider modularizing the modernization process to minimize disruptions caused by interdependencies.

  • Vendor Lock-in

Risk: Dependency on a specific vendor for modernization tools or services.

Mitigation: Choose technologies and vendors with open standards and interoperability. Evaluate the long-term viability of chosen solutions and plan for potential transitions if needed.

Role of Development Team in Successful Application Modernization

This blog tried its best to provide an overview of legacy application modernization, covering the best strategies to leverage it. But don’t forget that some software modernization pitfalls are involved with legacy system modernization, which is costly and time-consuming. Finding the appropriate team for your project is, therefore, crucial.

The dedicated development team plays a pivotal role in the successful application modernization process. Their responsibilities include understanding the legacy codebase, identifying areas for improvement, and choosing the appropriate modernization strategy.

The team must effectively collaborate to refactor or rewrite code, adopt contemporary architectures, and integrate new technologies. The development team’s expertise, commitment to best practices, and collaborative efforts are essential for achieving a modernized application that aligns with business goals and delivers enhanced performance and user experiences.

Seek advice from a business application modernization company if you are still trying to understand or are skeptical. As a well-known legacy application modernization company, we have helped numerous organizations across various industries by providing appropriate guidance for choosing the best legacy modernization roadmap.

Let’s connect to learn about our legacy application modernization strategies!

Frequently Asked Questions

How much does it cost to modernize your old application?

The cost of modernizing a legacy application varies widely based on factors like the chosen modernization strategy, the complexity of the existing system, required technologies, and team expertise. It can range from thousands to millions of dollars, depending on the scale and intricacies of the modernization effort.

Find the cost of React Native app development in India.

How to ensure the security of your crucial data during modernization?

Ensure the security of crucial data during modernization by implementing encryption protocols, conducting thorough security assessments, employing secure data transfer mechanisms, and maintaining robust access controls.

Which is the best legacy application modernization strategy for my project?

Choosing the best legacy application modernization strategy depends on project specifics. Evaluate goals, constraints, and desired outcomes to select the strategy aligning with project needs and resources. For example,

  • Rehosting is quick but may not optimize.
  • Refactoring enhances code without major changes.
  • Rearchitecting offers flexibility but requires significant effort.

Leave a Reply

Your email address will not be published. Required fields are marked *

Book a Meeting Book a Meeting
Call Us Call Us
Write to us Write to us
WhatsApp WhatsApp

fluent up