Mastering Legacy Application Modernization: Strategies for Success


The ironic truth of the business world is that change is the only constant. But this means that failing to keep pace with the competition and its technologies will only end with you falling behind. That’s where legacy application modernization enters the fold. When you modernize legacy applications, your team gains access to new features and functionalities.

Still, it’s inadvisable to update your software and tech infrastructure just for the sake of it, as embarking on a modernization journey without clearly defined objectives can lead to waste and pushback. After all, employees want to know the “why” behind changes, have a clear direction regarding what’s happening, and know how it will impact their day-to-day lives. 


The key is to pursue strategic upgrades that will further your big-picture organizational goals without disrupting the daily work of (or placing undue stress on) your team. And you must understand that its members may be a little apprehensive when you start reworking their work environment. 

As such, you need to support your legacy app modernization initiative with training, support, and change management strategies. On that note, we invite you to join us as we explore everything you need to know about overhauling your aging applications, including why you should and how to do so effectively. 

In this blog, we will cover:

Understanding Legacy Application Modernization

Legacy application modernization (also referred to collectively as legacy system modernization) is a process that focuses on updating and transforming applications to align with newer computing approaches, technologies, and business strategies. However, it’s important to know what constitutes a “legacy application” in the first place before pursuing a modernization initiative, as these are not just older pieces of software. 

A legacy application is a program that is obsolete or severely outdated.

In most cases, these solutions will still work, but they’re usually out of support and may even have security vulnerabilities that will never be patched. They may also have compatibility issues limiting your ability to integrate them with other tools. As part of a legacy system modernization initiative, you’ll often have to upgrade or replace these instances of old infrastructure and hardware, but there are certainly exceptions. 

The Case for Legacy App Modernization

why modernizeWhen contemplating legacy app modernization, you need to overcome the urge to simply step back and say, “Our current tools work just fine.” That’s not to say you should replace any piece of software that is a few years old, of course, but you cannot wait too long to modernize. Doing so can leave you at a competitive disadvantage. 

Why Modernize Your Apps?

Legacy application modernization is often a reactive conversation. You or one of your team members have identified a problem, and upgrading your tech represents the ideal way to overcome it. The precise benefits you’ll unlock through legacy app modernization will vary based on that problem and the type of software you upgrade or replace. 

Nevertheless, some general incentives to modernize your apps include the following:

  • Improving scalability
  • Increasing data visibility and accessibility
  • Supporting a remote or decentralized workforce
  • Replacing on-premise servers with cloud infrastructure
  • Decreasing IT costs
  • Promoting long-term technology goals
  • Accessing integrations
  • Enhancing team productivity and efficiency
  • Automating core workflows 

When you modernize legacy applications, your business is able to leverage the latest technological advancements, such as cloud computing, artificial intelligence (AI), machine learning (ML), and big data analytics. That transition not only enhances performance, scalability, and security but also provides a more flexible and agile IT infrastructure. As such, you’ll be more resilient and adaptable. 

Furthermore, modernization plays a critical role in attracting and retaining talent. Developers and IT professionals prefer working with contemporary technologies and methodologies, such as DevOps and microservice architecture. Modernizing legacy systems creates a more dynamic and innovative IT environment that can attract top talent and foster creativity. 

Evaluating the Impact on Business

There are no hard and fast rules for deciding when to replace legacy applications. Instead, you need to focus your decision-making process on solving business challenges and enhancing overall competitiveness. 

Here are a few questions you can discuss with your leadership team when evaluating the viability of a legacy system modernization initiative:

  • Is the app obsolete, outdated, or otherwise ineffective?
  • What are we going to replace the app with? 
  • What challenges are we trying to solve?
  • Will the replacement application eliminate a significant barrier to growth?
  • Will legacy app modernization improve the day-to-day for end users? 

Together, these questions should spur you to perform a high-level assessment of the business impacts of a legacy system modernization. You need a clear and compelling value proposition before embarking on such a major technology initiative. 

Planning for Legacy Application Modernization

Legacy app modernization is not an overnight project. Rolling out new technologies and acclimating your team to them can take months. Therefore, preparation is vital to your success. 

Anytime you are gearing up for a major IT initiative, you need to create a technology roadmap before anything else. It will chart your path forward, identifying key milestones and maximizing the odds of the process’s success. 

Beyond forming your roadmap, you’ll also need to accomplish the following steps:

Set Clear Objectives

Set objectivesEvery legacy app modernization initiative requires a clear objective. Don’t use vague language like “We want to replace a legacy app with a modern alternative.” You need to have a purpose and a detailed endgame. And once you’ve determined your primary objective, set additional goals and milestones to keep you on track and maximize the return on investment (ROI) of your initiative. 

Consider using the SMART goals framework, which breaks down into the following characteristics:

  • Specific: Make your goal narrow and focused 
  • Measurable: Ensure you can measure your progress and final results
  • Achievable: Make sure you can reasonably accomplish what you set out to do
  • Relevant: All goals must align with your big-picture objective and company values
  • Time-Bound: Set a clear end date

While it’s important to be ambitious with your goals, you don’t want to set your team up for failure. Still, it may be wise to build in a few contingencies just in case the unexpected happens. For instance, you create a detailed budget that includes some reserve funds to cover excess costs that you may not have accounted for. 

Choose the Right Modernization Strategy

Your legacy app modernization strategy should be tailored to the unique needs of your business. But regardless of such, most modernization efforts can be grouped into one of these five broad approaches:

  • Rehosting: Moving the app to a new environment without changing its code (i.e., moving from on-premise servers to the cloud)
  • Refactoring: Making slight modifications to an app’s code to make it perform better
  • Rearchitecting: Making significant changes to the app’s architecture to modernize it
  • Rebuilding: Rewriting the app from scratch while preserving its scope and specs
  • Replacing: Swapping an existing app with a more capable alternative 

Rebuilding (or rewriting) software makes sense if you love one of your existing tech tools but need it completely modernized. Conversely, replacing an app outright represents the best path forward when there are options that clearly outpace what you are currently using. 

Assess Your Current Infrastructure 

Your next step is to evaluate the state of your current infrastructure to ensure it can support modern, robust applications. If you are powering your business using an on-premise server network, you will need to migrate to the cloud as part of your legacy system modernization initiative. 

While a full-scale cloud migration adds new layers of complexity to the process, it will also provide long-term adaptability and significant cost savings. Cloud-based infrastructure offers predictable, stable IT costs, access to on-demand resources, and superior scalability. 

Execution of Modernization Projects

Once you’ve established your plan, it’s time to put your legacy application modernization initiative into motion. During this phase, you must do the following:

Go Incremental

legacy application modernizationIf you’ve ever switched from an Apple operating system to Windows (or vice versa), you know that the entire process of “jumping ship” can be overwhelming. While many of the third-party apps you use every day may stay the same, a large quantity of the core, proprietary programs on these devices vary significantly. Everything from sending a text to taking photos feels different.

All of that is to say that your employees will experience the same sense of confusion and sensory overload (on a much grander scale, too) during a legacy system modernization project. Fortunately, you can minimize these negative feelings and make the entire process much more budget-friendly by using an incremental approach.

Even if you must overhaul your entire architecture and tech stack, you can do so in phases. With such an approach to legacy system modernization, your team can get their bearings before you introduce the next application or software. Making the change as frictionless as possible promotes better user adoption and a condensed time to value. 

Ensure Continuity of Operations

Once you begin the rollout of your new application or system, one of your top priorities must involve ensuring the continuity of your operations. Even a momentary disruption in continuity can negatively impact your bottom line and leave you with hundreds of angry customers. 

Once again, keen preparation is key. You should have extra IT support resources on hand to put out any fires that emerge. Additionally, ensure that you’ve conducted extensive testing ahead of your go-live date. Dynamic testing protocols will allow your team to identify and remedy many issues before they impact your operations. 

Leverage New Technologies

Make sure that the application you are adopting incorporates the latest technologies, including cloud-based infrastructure, AI, ML, and automation functionality. Also, consider whether an out-of-the-box platform or a custom solution represents the best option for your business. 

The general rule regarding custom software is to source readily available solutions wherever practical and build bespoke solutions to maximize your performance. In other words, if there are already tools, services, or apps that meet your needs, use them. Custom solutions are ideal for addressing industry-specific challenges and accessing tools that are not already available.

Common Challenges & How to Overcome Them

Legacy app modernization is always challenging, but it doesn’t have to be a nightmarish process. By familiarizing yourself with what lies ahead, you can proactively address common hurdles and set the stage for a successful project. 

With that in mind, here are three challenges that go along with legacy application modernization you need to be aware of and how you can overcome them:

Managing Data Migration

Data migration represents the source of most modernization nightmares. It involves moving your existing application’s data to the new environment, and it can be a particularly daunting process if you are replacing your entire server-based infrastructure with cloud-based alternatives.

During the ramp-up to data migration, you need to identify where your information “lives,” clean it, and eliminate any of its inaccuracies. Doing so ensures a fresh start when you move over to the new environment. 

Given the broad scope of data migration, many businesses partner with third-party partners, like UDig, to streamline this process. You should consider doing the same, as a full-scale migration is likely to place a major strain on your IT bandwidth.

Integration With Existing Systems

Integrations facilitate data sharing between apps, thereby promoting information visibility and informed decision-making. However, integrating your newly modernized applications with existing systems represents another significant hurdle. 

For the most part, you can solve such a challenge during the app selection process. Prioritize technologies that have pre-built integrations that align with your existing technology suite. 

However, there’s a chance that an app won’t have all of the pre-built integrations you need. In that case, you’ll need to invest in custom integrations, which can drive up project cost and complexity. Factor those costs into your decision-making process to avoid budgetary overages or major project delays. 

Training & Change Management

According to a recent change management study, 73% of employees who are affected by an organizational change initiative report feelings of “moderate to high-stress levels.” It’s likely that these feelings can be traced to their fear of the unknown impacting their daily lives and overall job security. 

There are a few ways to ease your team’s worries. First, loop them in early on in the process. Inform them of the changes you are exploring, why you are doing so, and how the modernization efforts will impact their daily workflow. Clear communication works to ease fears of an unclear future. 

You must also put your team in a position to succeed by investing in training. Give them a chance to familiarize themselves with the new systems. Confident users will embrace technology modernization.

Ensuring Success | Legacy Application Modernization

Ensuring the success of a legacy system modernization initiative requires a strategic approach, one that starts with a thorough assessment of your existing systems and business objectives. You should also identify the key drivers for modernization, such as improving performance, enhancing security, or facilitating better integration with modern technologies.

Stakeholder engagement is crucial, so get users, IT staff, and business leaders involved from day one to ensure that the project aligns with both technical requirements and business goals. Clear communication and setting realistic expectations about the modernization process will help you manage change effectively.

You should also prioritize the following:

Measuring Outcomes

legacy application modernizationMeasuring the outcomes of a legacy application modernization initiative helps demonstrate its value and inform future decisions. Once you establish clear, measurable goals, you’ll be able to use key performance indicators (KPIs) to evaluate your progress. KPIs such as system performance, user satisfaction, operational costs, and ROI are also essential metrics to track. And regularly monitoring these KPIs helps in identifying areas where the project is meeting its objectives and pinpointing sources of friction. If you are stuck and need help quantifying the ROI on your project, check out our business case template. The template is an objective method to evaluate the ROI of your next technology initiative as it relates to your organization’s overall profit strategy. 

Use these measurements to validate your efforts and proactively address any shortcomings. For example, if your DevOps team is falling behind on the rollout of a particular feature, consider allocating additional staff and resources to that milestone. Pouring in additional resources will drive up project costs while pushing back the delivery deadline is often more costly. Therefore, it’s vital that you keep the project on schedule.

Finding the Best Solution, Not the Newest

New isn’t always better — just because a specific solution is new to the market doesn’t mean it’s the best thing for your organization.

So, when evaluating replacements for your legacy systems, you should also consider tried-and-true solutions. After all, a slightly older system that performs flawlessly and has a great design will receive a much warmer reception than a newer system littered with bugs and a clunky user flow.

Pay special attention to windows and workflows that users will be spending a lot of time on (such as data entry screens). You should also consider whether you can easily customize these screens for specific roles, which can further increase employee buy-in and make their jobs a lot easier.

Continuous Improvement

Adopt a mindset of continuous improvement to maximize the benefits of legacy system modernization. Regularly assess the systems and processes you overhauled to identify opportunities for further enhancements and efficiency gains. 

Encourage your team members to provide honest feedback. You want to address their pain points through targeted training, as doing so will maximize adoption and condense your time to value.

Incorporating agile methodologies into your workflows can facilitate ongoing updates and refinements. This ensures that the applications remain responsive to the changing business landscape. By fostering an environment of continuous learning and adaptation, your business can keep your technology relevant and impactful over time. 

The Future of Legacy Application Modernization

Moving forward, AI and ML solutions will be foundational elements of application modernization. These technologies will drive smarter and more adaptive applications that are capable of self-optimization and predictive analytics. 

Another significant development is the increased use of containerization and microservice architectures. These solutions promote even better scalability and flexibility, allowing your business to adapt to market demands swiftly. 

Altogether, it’s vital that you collaborate with a future-minded software development partner that has embraced these dynamic technologies. 

How Our Experts Can Guide Your Journey 

If you’re ready to embark on a legacy application modernization initiative, look no further than UDig. We invite you to explore our work, which includes application modernization for large unions and accelerating the speed to market for major financial organizations. 

Connect with UDig today, and let’s chat about your business goals. Together, we can unlock the power of modern tech and propel your business forward.  


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About The Author

Andrew Duncan is a Director of Software Engineering in Richmond, VA. He is a driven technologist focused on modern technology stacks and best practices. Andrew believes nothing is more rewarding than making software needs a reality with a focus on flexible, scalable and supportable code.