Succeed with an Application Modernization Roadmap

Bob Quillin

November 11, 2021

What Is Application Modernization?

Application modernization is the transformation of legacy systems into modern applications. This involves two core tasks – breaking up a monolithic application into microservices and moving the application to the cloud. 

There are several broad options available for application modernization, but the most common fall into two categories:


Rehosting is when you move applications from an on-premises environment to a modern cloud infrastructure. Companies opt for this approach when they are satisfied with how their legacy application is functioning, yet they want the advantages of being in the cloud. This approach has many advantages, such as minimal disruptions in service and a reduction in self-hosted data center costs. This option is also referred to as “lift-and-shift”, and while it may be the simpler one, most experts do not consider this modernization but simply migration.


Rearchitecting restructures a legacy application to make improvements while not changing any of its functionality. The application architecture is thus transformed from a monolith to a more microservices-based distributed system. This also results in the reduction of technical debt, performance improvement, cost-cutting, and upgraded platforms, programming languages, and tools. During this process, the necessary changes are made to run the application on a cloud platform. 

What Does Application Modernization Involve?

Application modernization is not only a technology transformation. You must also pay attention to updating the organizational structure, business processes, and people skills. A cultural transformation must accompany the digital transformation. This has to be deliberately planned at the start of any modernization project.

What Is an Application Modernization Roadmap and Why Do You Need It?

An application modernization roadmap is a set of steps that organizations should follow to achieve the transformation of their legacy systems into modern applications.

A modernization roadmap is not set in stone. It should be updated as new information emerges, technical advances gain traction, and engineers and managers gain experience during modernization.

Digital transformation is hard. According to the Boston Consulting Group, only 30% of transformations succeed. But laying out your plans and priorities on paper can increase the odds of success to 80%. A good application modernization roadmap is based on tested patterns and solutions.

Creating a roadmap at the start of the application modernization has many benefits.

Embarking on the application modernization journey is a major step toward leveraging technologies that help transform the company itself. It’s also a leap toward achieving digital transformation. And although the journey is daunting, a well-thought-out and rigorously reviewed roadmap can provide you with a sound launchpad to propel you towards success.

It isn’t wise for an organization to move all its applications to the cloud at the same time. You should first migrate those applications that can either be moved easily to the cloud or would provide big performance improvements or cost savings. A roadmap provides this level of clarity.

Related: Flip the Script on Lift-and-Shift Modernization, with Refactoring

How Should You Create an Application Modernization Roadmap?

Follow these steps to create a modernization roadmap:


Before starting your modernization journey, you must understand the approaches that are the right fit for your unique combination of applications and modernization objectives. 

In this step, you will understand your objectives in undertaking this exercise:

  • Assess what your current business outcomes are and compare them to what they should be
  • Carry out a detailed inventory of all the hardware and OS platforms, tools, and applications that are being used in your organization
  • Take a data-driven approach for modernization assessment that accurately measures complexity across all your application to help prioritize and size the effort

You will end up with a high level of awareness of where you are versus where you want to be. 


In this step, you will get a deeper understanding of what you need to do to get a competitive advantage.

You will understand both the business and technology goals which are driving the transformation. Based on this, you can identify the specific areas of improvement targeted both in your business and in your technology. 

On the business front, these areas may be customer satisfaction, innovation, and cost. 

On the technical side, they may be agility, quality, reliability, availability, and security. Achieving this may involve the judicious introduction of modern technologies such as migration to the cloud (this is covered in detail in the next section), or replacing applications with SaaS.

Identify goals

In this step, you should identify what to cut, merge, upgrade, or replace. Once you have this list, you can map out the ease or difficulty of modernizing each item versus the risk/benefit of modernizing. This exercise will help rank the order in which applications should be modernized. 

The planned and desired results of modernization are identified in this step: which applications are to be modernized, their prioritization, and how the modernization will be done. And the benefits that would accrue in each case.

You should consider these factors during prioritization:

  • anticipated performance improvement
  • expected cost savings
  • dependencies on other applications 
  • security controls required by the application 
  • services consumed by the application 
  • data required by the application 
  • the underlying technology architecture 
  • the effort required to rewrite code and configurations and conduct testing 
  • the costs of cloud-deployment options 
  • the business risks of performing a migration

Deliver roadmap and recommendations

In the final step, an actual plan of action for modernization is delivered. It would contain a list of applications to be modernized, related tasks, the modernization approach, and a timeline for completion.

Architectural and Technological Transformation During Application Modernization

Modernization starts with the architectural transformation of tightly coupled monoliths to loosely coupled microservices. 

To gain the greatest benefits from modernization, technological transformation is also necessary. You should adopt cloud-native technologies such as DevOps, automated testing, containerization, and serverless infrastructure. This brings down development and maintenance costs and improves operations.

This section takes a closer look at how these technologies help in modernizing your IT setup.


Legacy applications are built with a monolithic architecture – a single, huge program that includes all the components of the application. The application is usually deployed as one single unit, such as a JAR, WAR, exe, or something similar.

A microservices architecture consists of services that are small, independent, and loosely coupled. Microservices are small autonomous services that perform a single task, like updating a customer address. Converting a monolith to microservices is an essential part of modernization.  


Automated testing helps in reducing testing time, finding regression issues, and avoiding manual slip-ups, thereby reducing effort and costs. At the minimum, unit testing (testing of the smallest logically isolated unit in the system), and API contract testing (testing to verify that APIs are adhering to the documented request and response) should be automated. 

The CI/CD pipeline should include automated tests to provide instant feedback on breakages caused by check-ins. These safeguards provide the confidence that untested code will not be released to production.

Containerization and Orchestration

An application that contains a large number of discrete components makes it difficult to deploy, move between environments, and manage. To streamline deployment, applications should be packed into containers. 

Each container holds only the code (microservices), their parameters, and the required memory. Containers are lightweight and consistent. Their usage simplifies operations and reduces infrastructure costs. Containers are hardware-independent and therefore portable. They make application deployment a breeze.

Orchestration refers to the automation of many of the operational tasks associated with deployment. Kubernetes is the leading container-orchestration system. You can use it to deploy and manage containers. It is open-source and works on all major cloud platforms.


An option while migrating to the cloud is to use serverless technologies. Serverless does not mean that there are no servers. It is a cloud-based development model where the cloud platform provider manages the infrastructure by provisioning, administering, and scaling it. 

This allows developers to focus on building and running their applications without worrying about having to spin servers up and down. Developers only need to use containers to deploy. When a serverless app is idle, its cost is zero. Companies need to pay only for compute and not for the infra.


DevOps is a core component of cloud-native development. The principal purpose of DevOps is to facilitate handoff between development and operations. It includes the introduction of modern practices like Continuous Integration (CI) and Continuous Delivery (CD), and automated scripts to help with the management of cloud resources.


Security is an important aspect that should be kept in mind during modernization. Applications, data, and infrastructure must be protected. Cloud platforms provide security features that the applications and users must adhere to. Security should be embedded in DevSecOps processes and DevOps pipelines. Every application must have an associated identity and access management profile.

Operations / Post Modernization

The work of transformation does not end after the updated applications are deployed. The modernized applications require constant monitoring, and performance data generated by newly integrated tools must be continuously analyzed. Here are some typical activities which must be done in the post-modernization phase:

Build to manage 

Developers use a set of standards and solutions to make the application manageable and ensure that the application will meet service-level objectives.

Monitoring, tracing, and logging

Leverage observability and container platform tools to monitor metrics, traces, and logs to determine application health. Add alerting capabilities. Be proactive and fix things before users become aware that an issue exists.  

Communication and collaboration

Use tools and automation, including chat applications, and issue and project tracking systems to keep everyone informed.

Related: Migrating Monolithic Applications to Microservices Architecture

The Modernization Process

A roadmap provides a blueprint for the steps involved in modernizing legacy applications. It provides clarity of thought and action. The final, and most crucial step, is to execute on the roadmap. 

The process of transforming legacy applications to modern ones is difficult. It is labor-intensive, manual, error-prone, time-consuming, and requires deep architecture skills. Most organizations lack this.

You would have seen, in the earlier sections, that the most challenging tasks in creating a modernization roadmap are:

  • Understanding the structure, flow, and runtime functionality of legacy applications that may have been developed ages ago
  • Converting monolithic applications to a microservices architecture without breaking any functionality

How about an automated way of modernizing? Would that be any better? Wouldn’t it be nice if one could input a monolith into a software migration application (or platform) and a perfectly working microservices equivalent popped out? 

Ideally, such a migration application:

  • Speed up modernization projects, thereby saving money
  • Automate the rearchitecting and refactoring of complex apps, minimizing tedious manual effort
  • Be repeatable and self-service: monoliths in, microservices out
  • Intelligently and automatically transform complex monolithic apps into microservices
  • Analyze transactions, connections, and database table accesses and recommend refactoring of databases if required

Let’s look at what other capabilities such a migration application should have, and how it should work.


The application would perform static and dynamic code analysis, (and Data Analytics and Machine Learning if needed) to understand actual business flows.  It would then identify logical entities and their dependencies. 


It would analyze the complexity of the monolith to help prioritize and plan the next steps.

Refactor and Rearchitect

The application should get rid of dead code and deploy efficient, compact microservices. It should enable the design and extraction of a new services UI. It should contain low-code automation to convert a monolith into equivalent microservices in a scalable and repeatable way.

Other Benefits

The migration application should work regardless of the size or scale of your monolithic apps. It should offer the benefits of scale, development velocity, agility, upgradability, and cost. It should not negatively impact security, velocity, and scalability. The migration should be performed speedily and in an intelligent and automated fashion.

An Ideal Platform for Modernization: Does It Exist?

So, does such an ideal platform as described in the previous section exist today? It does. It is called vFunction. vFunction has been built from scratch solely to automate the modernization of legacy applications. How does it do this?

The platform uses advanced data science and machine learning techniques to identify business domains in the legacy monolithic app. It uses this learning to analyze, present, and then extract new system architecture models in which functionality is provided by a set of smaller applications, rather than by a single monolith.

The platform includes dynamic analysis and visualization tools that view the app running in real-time, and record how the app is behaving and what code paths it follows. This application analysis is then used to make recommendations on how to refactor and restructure existing code. These tools help maximize exclusivity (resources that are used only by one service), enabling horizontal scaling with no side effects.

Many companies attempt the decomposition process by using tools such as Java Profilers, Design and Analysis Tools, Java Application Performance Tools, and Java Application Tooling. But these tools are not designed to aid modernization. They can’t help in breaking down the monolith because they don’t understand the underlying interdependencies. So, they force the user to manually come up with a new architecture themselves.

The platform can handle code bases of millions of lines of code and can speed up the migration process by at least a factor of 15. The provided tools enable the modernization of apps (i.e., conversion from monoliths to microservices) in days and weeks, and not months or years.

Summing Up

vFunction is the only platform available today that intelligently and automatically transforms complex monolithic Java applications into microservices. It eliminates the time, risk, and cost constraints of manually modernizing business applications. vFunction delivers a scalable, repeatable factory model purpose-built for cloud-native modernization. 

vFunction helps speed up companies in executing their modernization roadmap. It helps them become faster, more productive, and truly digitally transformed. If you want to see exactly how vFunction can transform your application into a modern, high-performing, scalable, true cloud-native architecture, request a demo.

Bob Quillin

Bob Quillin is the Chief Ecosystem Officer for vFunction, responsible for developer advocacy, marketing, and cloud ecosystem engagement. Bob was previously Vice President of Developer Relations for Oracle Cloud Infrastructure (OCI). Bob joined Oracle as part of the StackEngine acquisition by Oracle in December 2015, where he was co-founder and CEO. StackEngine was an early cloud native pioneer with a platform for developers and devops teams to build, orchestrate, and scale enterprise-grade container apps. Bob is a serial entrepreneur and was previously CEO of Austin-based cloud monitoring SaaS startup CopperEgg (acquired by IDERA in 2013) and held executive and startup leadership roles at Hyper9, nLayers, EMC, and VMware.

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