Legacy applications often form the core of companies, supporting day-to-day business and offering necessary services. However, with advancing technology, the systems become dated, unproductive, and pricey to maintain.
Over a majority of businesses questioned in 2023 said that they modified their old software and information predominantly to make them more protected and well-run.
Reasons driving companies’ modernization, Statista
Almost half did so also to save costs, stay closer to new technologies, and improve adaptability in their systems. While compliance with regulations was the least common motivation, about 20% of companies still considered it to be important.
If everything is generally clear with the question of why, then how to carry out this process may not seem so simple. Today, we’re going to discuss the various methods of application modernization, key strategies, and tools that can help you through.
What Is a Legacy Application?
A legacy system is an aging software system that continues to be in use despite the existence of newer alternatives. Legacy systems are normally built using older technologies, and as a result, they are hard to uphold, integrate, and scale.
Legacy software can be unmanageable and bulky, but it often holds valuable business logic and data companies can’t do without.
Classic examples of legacy systems include mainframe applications, desktop programs, and software based on more aged programming languages, such as COBOL or FORTRAN.
Although the decision to modernize outdated software appears obvious, many companies continue using legacy solutions because they deeply penetrated nucleus business operations that are expensive and risky to replace.
Also, legacy systems usually support advanced or specialized business processes that the newer systems cannot easily substitute.
Why Modernizing Legacy Applications Is Crucial
Sustaining old software might be the less laborious choice but can, over the long haul, slow down business development, multiply risks, and force higher support, infrastructure, and staff costs.
Apart from that, legacy systems are prone to security vulnerabilities, which expose businesses to a greater chance of cyberattacks and data breaches.
At the same time, older systems can lag when it comes to changing regulations and compliance demands, which could lead to legal trouble and fines.
For example, if a business doesn’t follow PCI security controls and a data breach (that has credit card information) happens, it can be fined as much as $500,000 per incident.
Beyond technical problems, outdated systems can also hinder companies’ ability to compete.
Companies with obsolete software find it difficult to keep up with changes in the market, while companies that have adjustable, updated systems innovate quicker and swiftly respond to new trends.
The longer a company delays modernizing, the higher the chance of being left behind by the rest.
Lastly, legacy software does not get along well with new technology, thus making it harder to take advantage of cloud computing, artificial intelligence, and automation.
Legacy Application Modernization Approaches
According to Gartner, if you need to upgrade legacy software, the best approach depends on the problem you’re trying to solve. Some companies need a mere upgrade, but others need an entire overhaul. Based on this, you can encounter the following approaches:
Legacy application modernization approaches: quick comparison
Rehosting (Lift and Shift)
Rehosting, or “lift and shift,” is the simplest and quickest technique. It implies moving your application to a new platform without changing the code or architecture much. Rehosting is typically the default option for companies that must get to the cloud as quickly as possible.
Key attributes of rehosting:
- Minimal changes: The application is moved as-is, with no interference to the legacy code.
- Quick and affordable: The process is faster and generally cheaper than alternative approaches.
- Cloud migration: Typically signifies the move away from on-premises to the cloud.
- Basic infrastructure: Does not use cloud-native capabilities, such as auto-scaling or microservices.
When to use:
- If you need a quick cloud migration.
- When your current system is still functional but needs better scalability.
- If your primary goal is to slash infrastructure costs.
Replatforming
Replatforming goes one step beyond rehosting. It is the act of relocating the legacy system to the new platform, such as the cloud, but also performing some modifications to make it better aligned to operate on the new platform.
Main characteristics of replatforming:
- Adjustments to the application: While the basic application remains the same, there are certain application components (e.g., middleware, databases) that get revised to perform better in the new setting.
- Cloud optimization: Uses cloud services like managed storage, databases, and computing resources.
- Cost savings: Helps save costs on infrastructure through the utilization of cloud-based software.
When to use:
- When you have to move to the cloud but do not want to completely change the architecture.
- If your existing app just needs some sort of an update but not necessarily a full makeover.
- When cloud services can offer immediate improvements to system performance and scalability.
Refactoring (Rearchitecting Code for Cloud Optimization)
Refactoring goes visibly deeper. Here, developers must redesign or rewrite the application code and architecture to prepare the system for deployment to the cloud and strengthen its output.
Primary features of refactoring:
- Code restructuring: Certain pieces of code are restructured or rewritten to make it perform better.
- Adopting cloud-native functionality: The software can be broken up into microservices or rearchitected to use cloud features, for instance, auto-scaling and load balancing.
- Performance improvement: Refactoring solves the problem of getting better performance without wasting power.
When to use:
- Whenever you want to get an app modern and cloud-optimized to achieve its long-term viability.
- If you need your system to be more adaptable and expandable.
- If your legacy app suffers from performance bottlenecks or scalability issues.
Rebuilding (Full Reengineering of the Application)
Full reengineering implies totally rebuilding the legacy system from scratch to develop a new application that is more appropriate for the current conditions and technologies.
Main markers of rebuilding:
- Complete redo: The app is made from the ground up with new technology and prerequisites.
- Customization: The new system is designed to match specific company requirements.
- Not quick or cheap to do: Reconstruction is expensive and drains much time and resources for development and testing.
When to use:
- If your legacy software is outdated or can no longer react to the necessities of your industry.
- If you want to apply the latest technologies or components but they do not agree with your existing system.
- If redesigning or upgrading your existing app is even costlier than starting fresh.
Replacing (Transition to an Entirely New System)
Replacing the old system entails moving to a completely new solution, be it off-the-shelf software or a customized solution designed to go in line with current circumstances and future needs.
Some attributes of replacement:
- A new solution: The outdated app is completely substituted by a new software product or system.
- Integration with modern tools: The new system may be integrated with other modern tools and technologies.
- Staff training required: Staff might need to be trained to put into action the new tools of the new system.
When to use:
- When your legacy system falls behind your criteria, yet refactoring or rebuilding won’t bring the necessary progress.
- If you lack more recent components, but your old system is no longer relevant to offer them.
- When you must start afresh with a system that is more modifiable, universal, and open to tomorrow.
How to Conduct Legacy Application Modernization
Although the decision to modernize legacy systems seems to be the right one, it is not quite easy to know where to start and where to go.
Konveyor, for example, in its comprehensive report on software modernization suggests having a tangible goal and plan, enabling the right team, and constantly watching the system.
Performing a Comprehensive Legacy System Assessment
Prior to starting the modernization process, it’s necessary to determine the state of the legacy application.
This involves studying the architecture, performance, security, and business influence of the application. A proper evaluation will assist in clarifying the most appropriate modernization method.
Representing Business and Technical Purposes
Clearly explaining technical and other goals is important for directing the modernization process.
Regardless of whether the intention is scalability improvement, expense reduction, or user reception improvement, precise goals will assist in sorting tasks by importance and measuring success.
Choosing the Right Modernization Tactic
The chosen modernization approach should go in line with the business circumstances, budget, and timeline of the organization. A balance between the strengths and constraints of every approach needs to be struck to select the best match for the organization’s goals.
Prioritizing Applications Based on Business Impact
Not all legacy systems are alike. Prioritizing systems by business value allows organizations to concentrate resources on the software that will yield the greatest return on investment.
Securing Data Migration
Migration of the data would likely be among the most challenging elements of modernization. It’s important to confirm that data is accurately and safely migrated to the new system, with minimal disruption to the ongoing operations.
Overseeing Change and Pushing User Adoption
Any modernization endeavor will cause significant changes to user interfaces and workflows. Therefore, it’s crucial to oversee this change in a manner that provides impeccable transition, with adequate training and support.
Measuring Success with KPIs and Successive Optimization
Having explicit goals with performance indicators (KPIs) helps organizations track the pace of their system modernization. These should include speed, end-user acceptance, and overall enterprise impact.
But that is not all—system maintenance and enhancement are very important in guaranteeing the system is maintained in harmony with changing business needs.
Essential Tools for Legacy Application Modernization
When it comes to upgrading legacy systems, the right tools can make all the difference. Let’s look at some of the fundamental tools that businesses can rely on during modernization.
- Cloud Platforms (AWS, Azure, Google Cloud): Cloud platforms give businesses the resources and space they need to support modern applications. They make it easy to scale up, stay nimble, and stay secure—all while allowing for the upgrading and refining of current systems.
- Containerization (Docker, Kubernetes): Containerization makes the applications run everywhere they are hosted, becoming more portable and reducing technical problems. Some of the best tools used to improve legacy systems in this respect include Docker and Kubernetes.
- API Management Solutions (Mulesoft, Apigee, Kong): API management tools allow legacy systems to communicate with new technology by exposing their functionality through APIs. All in all, API development makes it possible for legacy applications to be integrated with cloud services, mobile apps, and other technologies without having to rebuild them from the ground up.
- DevOps and CI/CD Tools (Jenkins, GitLab CI/CD, Terraform): DevOps tools allow for faster development and simpler updates so applications stay up-to-date and easy to maintain. With the help of CI/CD tools like Jenkins and GitLab, teams automate updates and deploy new features without any problems.
- Low-Code and No-Code Platforms: No-code and low-code tools allow you to build applications in a few days without needing boatloads of coding skills. They’re great for modernizing existing systems, either building a brand new interface or bringing them onto trendy technology.
- Data Migration and Integration Tools: Data migration tools make it easier to move data from old systems to new systems without any problem. Integration tools enable the connection of old systems to new technology so that everything can work together in harmony.
Challenges in Modernizing Legacy Applications and How to Overcome Them
Modernizing legacy applications isn’t always easy, but with the right approach, it won’t be a problem.
Migrating the legacy system to a new system is one of the most difficult challenges. Legacy software accumulates tons of data, and transferring the data to a new system without losing it or causing errors may be a complicated process.
The key here is to plan ahead—using the right data migration tools and doing a lot of testing to make sure everything moves over properly.
Another problem is the administration of older system dependencies. Most older programs rely on earlier software or hardware that may become outdated, making the upgrade even more problematic.
To avoid these headaches, businesses must start out by mapping out all system dependencies. When they know what is attached to what, they can gradually upgrade or substitute the outdated pieces instead of trying to change everything at once.
Then there is the skill gap problem. Older technologies are less prevalent these days, and fewer IT personnel understand how to handle them. That leaves companies potentially short-handed when it comes to the expertise required to meet their modernization efforts.
The best approach to do this is by investing in staff training or the recruitment of professionals who have experience with newer technologies. In this manner, the staff has the skills needed to make the transition a success.
And then, of course, there’s downtime risk. No business wants to deal with interruptions that extend operations or annoy customers.
The best way to avoid downtime is to move in increments. Instead of making radical changes all at once, companies can roll out updates incrementally, test them before releasing them, and have fallbacks ready in case they fail.
Legacy Modernization Strategies & Future Trends
As companies look to the future of updating their legacy software, several trends are truly going to influence how the process unfolds.
Firstly, serverless computing and microservices will become more popular. In serverless computing, companies will not have to manage servers—they will be able to just run their applications without having to worry about infrastructure.
Next, there will be even more companies utilizing hybrid and multi-cloud architectures.
Instead of confining themselves to one cloud vendor, they’ll use a mix of private and public cloud solutions so that they can enjoy the benefits of both.
Such an arrangement will give them more flexibility, better reliability, and more control over their data, and it will also prevent them from locking themselves in with one vendor.
In the meantime, DevOps and agile practices will be prominent drivers of modernization. They allow businesses to deliver more frequent small updates, thereby allowing them to make rapid adjustments to alterations.
Finally, Digital Adoption Platforms (DAPs) will make it easier for employees to learn and adapt to new systems. These platforms come with embedded training and support, guiding the users through the transition so they can quickly learn.
The Role of AI in Software Modernization
The majority of business owners view AI as one of the key drivers of modernization. More than half of the firms surveyed include it as among the many reasons why modernization is necessary nowadays, while nearly two-fifths of the firms saw improvement in their move towards modernization using AI.
Optimization for performance is the most common use case by far—complex distributed systems increasingly exceed the capability of humans to properly fine-tune them by hand.
However, automation of manual labor in general and testing/QA specifically are also very important uses for AI.
Directly assisting in code generation, though, seems relatively immature and was less often mentioned than other uses even with the buzz (and sometimes furor) around large language models (LLM) in most developer communities. Still, everything may change soon.
How to Choose a Legacy Software Modernization Company
When picking a company to help with modernization projects, you must be sure that they have the right experience and knowledge.
You should pick a company that has experience handling systems of your kind and has the right technical know-how to get the job done. They must have a proven process and be easy to communicate with throughout the project.
SCAND is a great option for the legacy system modernization. Having spent decades working with .NET and possessing a profound understanding of the latest tech, we are all about bringing your systems up-to-date and having them perform more effectively.
Our team will closely collaborate with you to make sure the whole process goes as flawlessly as possible and that you’re well set for the long term.