Legacy Software Modernization: A How-To Guide [feat. MythBusting]

The digital world is pushing businesses forward provided that they accept the rules. Staying competitive is possible only if moving with the times. Millions are spent on expanding the online presence and keeping the software up-to-date. 

What Is Legacy Software?

Legacy application means the obsolete system, developed using the outdated technologies. 

But in most cases, legacy software keeps working and complies with all the functions that prevent the product owner from replacing or modernizing the legacy. 

The must-use technologies become increasingly irrelevant in 3-5 years, as well as the decision logic and architecture patterns. That’s why, the majority of tech products have a 5-year lifecycle. 

Customers, inspired by the best user experience practices and stunning web designs require more and more, frequently preferring the brand-new products over the legacy applications.  

Thus, increasing business value of the legacy but still live application is the way to maximize the revenue, attract and re-engage users, beat the competitors, and convey the modern vision to the market.

Legacy Software Modernization: Myth Busters

Myth #1

“We don’t need to modernize legacy software as it’s still working”

It seems to be a reasonable statement, as in most cases legacy modernization consumes much time & budget plus the risks are high. These are concerns eating up a business runner, but are they really relevant? 

Here are five things that can be done better under the condition of software modernization to bust the myth:

1. Integration. It’s all about integrations in the modern digital world. Saas, on-premise, and application-to-application integrations are only possible for up-to-date systems. 
2. Security. Vulnerability of the legacy applications to all kinds of cyberattacks and data breaches is a well-known fact. Do you really want to compromise your customers by letting them use legacy software? 
3. Support. The older the application is, the harder is to support it. Especially if you are working with the third-party vendor. Especially if nobody from in-house team has a comprehensive understanding of the way it works. You’re two for two? Risky you are! 
4. Mobile-First Approach. Of course, a growing need for a mobile optimization may not affect your application. Or may affect. So, if your niche assumes mobile users, considering proper optimization is the first thing to do. Meanwhile it’s almost impossible to optimize the legacy applications. 
5. Business Performance. To meet growing business needs, your software should first meet the modern demands the market makes. Lack of scalability and flexibility will negatively affect the business performance.

Myth #2

“The cost of legacy modernization is too high, I’d better keep on maintaining my application”.

You will probably be surprised when know that support of obsolete apps consumes the most of the budget:

This spending mostly includes the maintenance of legacy systems that may result in inefficiency, security gaps, thus, million risks issues. And this is only the tip of the iceberg, as giving an estimate is possible only after thorough examination of a specific application. 

As you can tell, only 20% of a budget is usually spent on adding new features to meet the customer demands. It means you leave less room for adoption of new technologies that could emphasize your competitive advantage. 

Another problem is that new features are added into the legacy code turning the complex systems into the sophisticated ones and interfering with taking a decision on application modernization. The outcome is simple: the cost of your application modernization is going up every day. 

The last thing to say, there actually are the cases when it’s better to leave the system as it is, and the essential is to find the consultant(s) who’ll help you make the right decision.

Myth #3

“It would be easy peasy lemon squeezy. Let’s just rewrite all from scratch!”

Another extreme the people who’ve never done the modernization may go into. It will be a lucky break if somebody tells you: “Difficult difficult lemon difficult” and warn of the biggest software modernization challenges. 

Unfortunately, in the real world you may not be so lucky, as contractors love such extensive and complex projects that could legitimely drag on for years. 

The multiple reasons can prolong the process of app modernization starting from improper scoping or poor planning to the lack of familiarity with the system’s functions resulting in non-implementation. 

Think ten times if your vendor with a great zeal submits you a complete re-write plan. Or, at least, make sure this plan is comprehensive. Learn from the example of California’s DMV IT Project and don’t jump into it too quickly. 

Steps to Modernize Your Legacy Software

Architecture audit. High-level application architecture audit is the first step to identify the problem areas and decide on the proper strategy of a system modernization. 

In addition, architecture audit helps solve the problem of absence or lack of project documentation inherent in most legacy software. 

The application architecture is worth being examined at least to understand what code should be reviewed during the next step. Of course, if the quality of the application is low, it’s possible to identify the majority of mistakes already on the stage of the architecture audit.

In some cases, we can’t do without an intervention in an app architecture, as in general, most legacy systems are monolithic applications. This fact makes difficult to modernize the app components whether it is scaling a certain part that requires it the most, or adding the functionality. 

Fact remains that monolithic architecture doesn’t allow changing a system part in isolation. Modifying the functional unit is impossible without modifying the whole structure of the system. Replacing monolithic applications by modular ones precisely for adding flexibility is one of the solutions the modernization is aimed at. 

Code review. A comprehensive code audit allows identifying and analyzing the bugs, as well as forecasting and preventing the code vulnerabilities. 

In addition, we shouldn’t forget about technical application support. Unfortunately, no exact statistics are available, but most researchers are positive that approximately half of all time allocated to maintain the application is spent on reading the already written code to add new functionality, fix bugs, integrate into new environments, etc. 

That is why cleaning up the code mess is a must-do during the legacy software modernization for app modification and expand the functionality. 

Performance Testing. The main objective of the performance testing is the identification of the application’s stability, work performance, and amount of resource consumption, and other attributes of quality in different use scenarios and loads. 

Such tests allow detecting the flaws and system bottlenecks to define and prioritize the application parts that should be scaled during the modernization, as well as the modernized system work performance requirements. 

After the legacy system has been analyzed and weak points have been detected, we can move to modernization that may include the following steps: 

Refactoring. Refactoring is a process of amending the application system in such a way to change only the internal code structure making it simpler and clearer without influencing the result. 

This activity is aimed at streamlining, structuring, and systematization of chaotic (for certain reasons) code, debugging, and improvement of the application performance. 

Unit Tests. Automatic unit tests are a crucial part of the software modernization process. It would be better if the application is upgraded in the format of short iterations accompanied by writing and running unit tests. Their value lies in detecting the errors right away and ensuring the application’s efficiency. 

In the perfect world, developers would run these tests each time when compiling to keep the process of app modernization under control. 

Cloud-Based Integration. Cloud computing promises a bunch of benefits for businesses, including the possibility of continuous integration and delivery during the process of legacy app modernization.

The concept of continuous integration & delivery (CI/ CD) offers as its name suggests, the assembly line of code testing and delivery with the opportunity to continuously merge the recently written code in the mainline one. In other words, a developer submits only the small application segment, accompanied by unit tests (as it’s been mentioned above) to make sure the code fulfills the functions envisaged. 

CI/CD are the vital steps to modernize your legacy application that simplify the further support and cycles of updates.

Reverse-Engineering. The software documentation that is a basis of building the modernization strategy when working on legacy tech projects can often be incomplete, obsolete, or absent. Based on our experience, reverse-engineering is the best practice to apply in such cases. 

The main objective of the reverse-engineering process lays in researching the application design to understand its work principles and mechanisms and find the undocumented features for further project modernization.

Do I Really Need to Have My Application Modernized?

There is no common answer. Only a dedicated team may respond to this tricky question after a thorough analysis of your system. That is why the hardest part is to find good vendors or consultants who will help you draw up a comprehensive plan and set up the processes even if it is your in-house tech team who will work on software modernization. 

This solution may become a panacea for your business provided that the approach is correct. Choose wisely!