Application Modernization

Application Modernization Definition

Application modernization, also called application development modernization or legacy application modernization, is the practice of updating older software for newer approaches to computing, including newer frameworks, languages, and infrastructure platforms.


This practice works in software development the way that home renovation works for people shopping for a new home. In homes, people renovate an existing home so it’s modern and up-to-date instead of building a new structure.


In software development, legacy application modernization services allow businesses to improve the security, efficiency, structural integrity and other features of an existing system rather than replacing it entirely. Legacy modernization enables organizations to have both modern technical innovations and extend the lifespan of their applications.

What is Application Modernization?

Application modernization is the process of updating the internal architecture, platform infrastructure, and/or features of existing legacy applications. Application modernization services migrate legacy applications to new platforms or applications, and integrate new business functionality. Application development and modernization options include re-hosting, re-platforming, rearchitecting, recoding, re-engineering, interoperability, and at times retirement or replacement. To ensure the correct choice, the application architecture should also be altered.

Diagram depicting the components of application modernization.

Much modern application modernization discussion focuses on massive, on-premise applications that are typically maintained and updated via waterfall development. The challenge for application modernization is how to bring these applications into microservices, DevOps cloud architecture and release patterns.

What is the Application Modernization Process?

As mentioned above, the most common application modernization process involves breaking down and refactoring a monolithic applications into multiple smaller, loosely grouped microservices. There is more than one way to approach this challenge.


One approach is to take it in “chunks” by creating a new application alongside the legacy application that can replace it gradually. This is called the “strangler pattern” because it selects the most valuable and accessible parts first, rather than breaking down the monolith at once. Eventually as this approach goes on, there’s nothing left of the monolith and the new application has only the best pieces of it, all working together.


Cloud migration is nearly always part of the modernization process. Although the simple lift-and-shift of applications without doing a substantial rewrite is possible, the real value of application modernization is more often found in restructuring the application to leverage Kubernetes, containers and cloud native solutions to better take advantage of cloud models.


Another approach to application modernization may leave an application in place but expose its functions or data securely via APIs. This approach is based less on application migration and modernization and more heavily on integration yet enables modern, cloud native applications to access the capabilities of existing data and systems.

What are the Core Application Modernization Steps?

Several common application modernization and migration trends have led to several distinct techniques:


Rehosting or Lift and Shift


Called either “lift and shift” or rehosting, this application modernization software development phrase refers to moving an existing application from a legacy environment such as an on-premises server essentially “as is,” with few, if any, changes to its underlying architecture or code, to newer infrastructure, such as a public cloud platform. This approach is usually the least intensive, but depending on the application in question, may not always be the optimal choice.




Refactoring refers to the approach to application modernization that restructures, retools, or rewrites significant chunks of a legacy application’s underlying code to better suit it to run in cloud infrastructure or some other new environment. This approach often demands major restructuring of the existing codebase in addition to rewriting code. Yet if a development team wants to break up a monolithic application to achieve microservices—an architectural choice involving smaller, decoupled pieces—they might choose this approach. Microservices including containers and container orchestration can maximize the benefits of cloud-native tools and infrastructure.




An approach that is a sort of compromise or middle ground between refactoring and lift-and-shift is the replatforming pattern. This approach does not demand the major changes in architecture or code that refactoring does, but enables the legacy application to access a modern cloud platform by delivering complementary updates such as modifying or replacing the backend database.

Why Application Modernization?

An application modernization strategy is a key piece of the overall digital transformation plan for any enterprise. Application modernization platforms allow an organization to refresh its application portfolio and protect its investments to take advantage of technological progress such as contemporary tools, infrastructure, and languages. A robust strategy for portfolio application modernization can increase the reliability and frequency of deployments, reduce the resources needed to run an application, and improve resiliency and uptime, among other benefits. When you modernize an application you have the opportunity to implement modern approaches, fuel further innovation, and inject intelligence into the application.

What is Enterprise Application Modernization?

At the enterprise level, an existing portfolio of applications represents significant operational and financial investments. In this sense, “legacy” refers not only to the age of software, but also time and effort investment into the applications that are most mission-critical to the business.


Thanks to the depth and breadth of these investments, few organizations are able or willing to simply retire and start over when it comes to legacy applications. Productivity losses, costs, and other issues are too great to justify this kind of decision. An enterprise scale legacy application modernization framework is therefore the most practical way for many enterprises to take advantage of newer software architectures, libraries, platforms, and tools.

What is a Legacy Application?

A legacy system or application in computing is an old technology, method, or program that is still in use even though it is an offshoot of or related to a former or outdated computer system. Legacy applications and systems often pave the way for their successor systems, but because they are obsolete in many ways, it can be a challenge to keep them functional while converting them to more modern, efficient code.


Legacy applications still work, but because they are outdated or obsolete they are more likely to be less stable than modernized apps. Some legacy application modernization examples include Windows 3.1 applications that were still operating when Windows 95 was introduced, or mainframe applications that continued to operate after the move to client/server networks. A legacy application is just an application that was written for an earlier hardware platform or operating system.

What is Legacy Application Modernization

Legacy application modernization is rebuilding or updating an outdated application to work effectively with other applications in modern runtime environments as part of the organization’s application portfolio. Legacy modernization is a process of optimizing and updating business systems to address technological constraints, gain operational efficiencies, support integration and adoption with other, newer platforms, and improve user experience.


Approaches to legacy modernization can vary significantly. On the more intensive end of things, a team and organization may opt to re-architect the system completely, and build a new system using cloud native development tools to replace the legacy system. A less intensive approach is to use migration tools to refactor code and run the same system on more modern infrastructure with minimal code changes. In some cases, it may be possible to avoid code changes altogether by using an emulator.

Why Modernize Legacy Applications?

Legacy applications tend to be monolithic applications with two features that make modernization important: they are challenging and costly to scale, and difficult to update.


Monolithic, legacy architecture is difficult to update because all components of an application ship together. This means integration and adding features is inherently costly and challenging.


Scaling monolithic applications is costly and challenging for similar reasons. In fact, it can become necessary to scale up the entire app if even one component is facing performance  and  load challenges, which likely means substantial wasted compute solely to serve the most-demanding application components.


Instead, it’s possible to scale and deploy application components that are more loosely coupled and smaller independently with application modernization microservices architecture. To be sure, this approach presents its own challenges, but also delivers more of the core value in modernization.

Application Modernization Checklist: Steps to Modernize Legacy Applications

There are several important legacy application modernization strategies. This application modernization checklist and its steps can aid organizations on the path toward digital transformation:


Make the Business Case for Application Modernization


Ask and answer several business questions: Who benefits if we modernize the application right now, and what new opportunities will it present?


Conduct a full application assessment, detailing the value of each app to the organization, its role in customer experience, and the anticipated difficulty or ease of modernizing it. Tackle anything with high value and low effort first. High value apps that are also high difficulty may need their own strategies.


Preserve Core Software “DNA”


Many applications don’t need to be rewritten entirely from scratch even when an organization decides to update. Instead, it’s possible to modernize the core “DNA” of the original software to better meet current business needs.


Determine Which Metrics to Use


As your team determines which metrics will measure progress on the road toward application modernization and rationalization, conduct a risk assessment of each option. Consider that each organization must modernize applications and measure progress toward transformation across multiple pillars: architecture, technology, and organization.


Architecture Transformation


App modernization begins with the technical transformation of architecture as many organizations move away from tightly coupled, three-tier, hard-to-change monoliths in favor of loosely coupled, agile, modern, microservices-enabled landscapes. The journey is intended to achieve greater agility and flexibility, but it begins with the right framework for application modernization architecture.


This framework implements best practices focused on simplifying application development and maintenance cycles and includes domain-driven patterns of industrial design. In a classic cloud-native architecture pattern, monolithic applications and complex business domains are broken up into smaller data-driven microservices with each context subject to clearly defined boundaries.


An API-first design approach ensures compliance with governance and security requirements and conformity to enterprise-wide consumption needs. Asynchronous architecture adds autonomous behavior that allows for parallel builds and faster deployments, and reduces dependency on complex integrations.


Technology Transformation


To glean maximum benefit from application modernization, it’s essential to adopt modern, cloud-native technologies such as serverless microservices, containerization, and PaaS. However, due to the massive scale of modernization, the focus must include establishing quality automation and DevOps pipelines to continuously drive down maintenance and development costs and help enhance operational excellence in addition to updating functional capabilities. Additionally, organizations shift away from limited re-use and on-premises technologies and infrastructure to leading-edge PaaS tools in custom, traditional, and public configurations.


Organizational Structure Transformation


Traditional development approaches pool separate resources to support infrastructure, development, and quality assurance with large teams for each project. However, to support modernized application architecture, it’s critical to break down silos across quality assurance, development, testing, infrastructure and business operations and replace them with domain-driven teams that are self-sustaining. The modernized approach must fuel platform operations, development, and automation scripting with the same resources.

Application Modernization Technology in the Real World

Several intersecting technologies are fundamental to the application modernization process most organizations experience. These are some basic application modernization recommendations:


Cloud Computing


Cloud computing is so essential to application modernization that the process of migrating traditional applications to run in modern cloud environments is typically what people are referring to when broaching this topic. This includes public and private cloud platforms, as well as hybrid clouds which generally refer to on-premises integration of a system with public and/or private clouds.


And although the public cloud is a core aspect of any cloud application modernization strategy, there are also crucial latency, security, and architectural reasons for private cloud, multi cloud, and hybrid cloud strategies. The different cloud models can assist various kinds of organizations in solving for their own unique policy and architectural complexities if they’re not ready to migrate straight to the public cloud from the data center.


Application Modernization With Containers and Kubernetes


Containers and Kubernetes are means of holding, deploying, and operating workloads and applications. Containerization offers various benefits, including greater portability, scalability, and operational efficiency that is particularly well-suited for cloud, multi-cloud, and hybrid cloud infrastructures and environments. Containerization enables the consistent yet flexible, lightweight packaging of applications so that they can run across cloud, desktop, or on-premises environments.




This is an architectural choice more than a technology, yet it offers similar benefits to a more advanced technology. Rather than monolithically developing one complete codebase and operating it as an application, the organization decouples various components that can be independently updated, deployed, and operated.


Orchestration and Automation


In software development, orchestration refers to the automation of many container-related operational tasks, including scaling, deployment, and networking. Automation is a critical technology necessary to sustainably manage modern applications at scale.

Application Modernization Market Trends

A recent 2021 report projects that the global enterprise application modernization services market will reach USD 43.35 Billion by 2026, from USD 16.2 Billion in 2019, during the period 2021 to 2026 at a CAGR of 15.1 percent. The report segments the market by type and application.


Due to this market expansion, the ongoing need for the scalability and flexibility of cloud services, growing demand for updating older applications and systems, increased drive for improved customer experience from applications, and the rise in remote work scenarios, growth is likely to continue. This growth will be supported by the scalability of cloud-native applications, but the ongoing need for improved software functionalities should fuel the growth of the application modernization market.

Cloud Application Modernization

Generally, any discussion of application modernization principles refers to the process of migrating legacy applications to the cloud. As a basic matter, net application modernization involves ensuring applications can run in modern cloud environments.

Docker Application Modernization

Frameworks such as Kubernetes and container engines such as Docker package applications in a standardized way—including runtime, code, and libraries—encapsulating an application and its required environment to create new agile, scalable cloud-native applications. This method of modernizing legacy applications enables them to run consistently across their entire software development life cycle and different computing environments.


Enterprises that must manage and deploy hundreds or thousands of Linux-based application containers can benefit from container orchestration which automates the management, deployment, networking, and scaling of containers. It also eliminates the need to redesign applications and can simplify the deployment of applications across different environments.


Application modernization and containerization are closely linked because containers can be hosted anywhere. This means that the containerization path enables simpler refactoring and an easier route toward service-oriented architectures (SOA). What once ran as a single stack on one server can be refactored as a cloud-native application to run as a service on the cloud.


Containerization offers various application modernization and optimization benefits in the cloud:


  • Flexibility. Containerization promotes agility and scalability, allowing applications to shrink to meet IT demand and grow to full capacity without triggering problems in security, performance, or scalability.
  • Secure and Compliant. Containerized applications offer enhanced security, because they are isolated.
  • Designed for the Cloud. Containers are designed and purpose-built for the cloud, so they always have the latest patch, release, and updates.
  • Lower Costs. Reduces the cost of cloud application support and maintenance.
  • Improved Efficiency. Empowers IT staff to automate management and focus on critical tasks such as code development instead of wasting time resolving housekeeping issues.

Gartner predicts that over three-quarters of global organizations will be running containerized applications in production by 2022, up from less than 30 percent in June 2020. By offering agility, portability, scalability, and security, application modernization opens up new business opportunities to the organization and equips the enterprise to better differentiate itself from the competition and leverage the benefits of cloud computing.

Application Modernization Testing

Delivery teams must take every opportunity to assess quality with application modernization testing throughout the modernization and optimization journey. Using a combination of test service virtualization and automated testing can help teams with application modernization assessment and deliverable quality throughout the software lifecycle.


It is important to select the right tools to enable continuous software testing through the DevOps pipeline. Consider product architecture, design, and scalability; ease of use and deployment; and vendor services and user support as you choose application modernization tools and application modernization companies.

Application Modernization Challenges

Typically, application modernization challenges can be reduced to cost and complexity. Many applications might significantly benefit from rearchitecting or replatforming but are coupled closely enough to existing infrastructure and systems that the complexity of legacy application modernization approaches outweigh their benefits.


That said, there are several more specific application modernization challenges that many organizations face:


Cost and Duration of Application Modernization


Budget overrun is the worry of every project manager and organization. ROI rules any project, including application modernization.


Existence of Massive Legacy Systems


Application modernization is particularly daunting for organizations with a large footprint of legacy systems, demanding careful management in stages. Business continuity should be at the heart of all application modernization methods.


Integrating Infrastructure


Organizations often prefer to retain some existing application software built and deployed on infrastructure on-premises. However, with some apps in the cloud and others on-premises, operational silos and other inefficiencies can arise if the apps are not properly tenanted and integrated to offer a complete 360-degree view.


Change Management for Legacy Systems


It is difficult to find teams to manage legacy systems that can be decades old, yet migrating them to modern platforms in single steps is complex and risks data loss. It is not always possible even for experienced teams to re-create all logic from the existing database or understand how legacy apps were created.


Misalignment of Business and Technology Teams


This kind of misalignment can result in data stores and applications that are redundant; inefficient cloud use and associated costs is a good example.


Failure to Integrate New Applications


Point-to-point integrations are not possible when hundreds or thousands of apps are constantly being spun up as the business process changes. Yet if these cloud apps exist in silos, modernization fails.


An API-Only Approach is Too Common


It is easy to bring legacy applications online and into the cloud by adding cloud APIs onto them, but “cloud-washed” apps like these usually are difficult to scale. APIs are important to application modernization but the process often also relies on breaking down monolithic applications into microservices, not just the presence of an API. Often companies scale the API but the legacy applications cannot accommodate the increased load.


Complexity of Application Modernization Tools


Many existing application modernization tools and other application modernization solutions are difficult to use and master, demanding special training. This increases reliance on application modernization vendors, which is a mixed bag for many organizations.


Cloud Security vs Legacy Security


Unfortunately, there is no strict like-for-like swicth when you migrate to the cloud; what existed on premises does not necessarily exist in the cloud. For example, your on-premises firewall will not work in the cloud, and another tool, platform, or service will take its place. Application security and application access must be reviewed, planned, and updated. 

Application Modernization Best Practices

Ultimately, the key to successful application modernization comes down to strategic selection of projects that offer a clear path to enhanced ROI and customer experience.


Understand Each Application and its Dependencies in Detail


Learn how each application performs in its current environment, how different conditions affect how it operates, and how the app integrates with other parts of the ecosystem. This type of research helps the team develop individual application modernization roadmaps and make data-driven decisions.


Prioritize Applications to be Modernized


Next assess the pros and cons of modernization for each application, identifying priority projects as well as those that can be modernized later. Identify and describe the associated risks of modernization for each application as part of this process and select the best approach. Quantify the goal benefits for modernization in terms of improved scalability, agility, performance, and reliability, and evaluate the cost and time budget for each application modernization project. For example, business application modernization projects will have unique goals compared to payment application modernization projects.


Determine the Web Application Modernization Strategy


Determine which modernization strategy best suits organization needs and business goals.


Have a Data Migration Checklist in Place


Document how the old system represents data, how it needs to be migrated, how to test to ensure the migrated data is relevant, accurate, consistent, and updated. This enables the team to understand what data is important and has to move.  Also, when staging data in a cloud development or UAT environment, anonymize the data and address poor security practices like passwords stored in clear text.


Overcome Resistance Quickly


Existing users are used to operating legacy desktop applications, so application modernization typically prompts some resistance and pushback. Before the modernization process begins, it is crucial to communicate the need to modernize the application, and the benefits the process will offer the team.


Embed Security at Every Step


Poor security is a major problem for legacy applications, and left unaddressed, this issue can lead to security risks that are organization-wide. Embedding security diligently at every step of the application modernization process is key to success. Detect security challenges in legacy systems with security tools and repair them as quickly as possible. Encrypt data and implement strong authorization and access control measures.

Benefits of Application Modernization

The benefits of application modernization are generally summed up as follows:


Improved Functionality. Expose the functionality of existing applications to be consumed via API by other services.


Business Agility. Improve speed of new feature delivery and with it organizational capacity to respond rapidly to new threats, opportunities, and demands.


Scale and Performance. Replatforming applications to the cloud from on-premises data centers to improve application performance as scalability also enhances long-term IT and data center strategy.


Transformation Roadmap. The application modernization strategy creates a roadmap for digital transformation and a tactical vision with measurable outcomes for the business.


Data Estate. Modernizing applications creates infrastructure and architecture for interconnected data that the organization can tap for data science practices such as business intelligence.


User Experience. Application modernization patterns enable more relevant and meaningful user experiences.


Cost Savings. Enterprises that modernize applications with cloud migration can free resources to put toward the core mission rather than infrastructure management. Furthermore, the automation, breadth of services, and scalability of the cloud can achieve significant cost optimization over time.


Maximize Existing Investment Value. Hybrid environments can maximize enterprises’ abilities to use existing solutions and enable integration between cloud native solutions and legacy applications.

Application Modernization Services by Provoke Solutions

Provoke Solutions offers application modernization services that future-proof your IT infrastructure. The Provoke team focuses its depth and breadth of experience and capabilities to select only the services you want and need that prepare your company for the future.


As a Gold Status Microsoft partner, Provoke objectively assesses the enterprise applications of clients moving to an Azure cloud-based architecture. Provoke’s Azure migration plan systematically ensures that assets are securely migrated with minimal downtime. Learn more about how we help clients with application modernization services.

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