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February 8, 2024

Key Strategies for Modernizing your Legacy Applications and Systems

Legacy systems have helped many companies get to where they are today, but those same applications are the ones that, sooner or later, become obsolete over time and slow down business growth.

Upgrading obsolete systems and applications is crucial for a company to continue to ensure success, make better decisions, and create a well-thought-out IT strategic plan. We tell you how to approach it and choose the strategy that best suits you.  

What is a legacy system?

Legacy systems refer to any software, technology, or process used by an enterprise that is no longer as effective as it once was or has become obsolete.

As applications and systems enter legacy systems status, they add challenges and risks associated with outdated technologies to the business, such as hacked integrations, lack of support for third-party integrations, security threats, and compliance risks, poor customer experience, etc. 

Legacy System Modernization 

The modernization of legacy applications involves replacing these obsolete systems with new solutions that make use of modern architectures oriented towards obtaining the maximum benefit provided by the cloud services available between the different hyperscalars. This involves analyzing current solutions, migrating them, and incorporating new features that make use of the new technologies available on the market.

It may initially seem daunting and difficult, but working with obsolete IT systems is even more complicated and dangerous. Opting for this modernization will result in more efficient processes, teams, and customers with better experiences, resulting in reduced costs and risks. 

Benefits of modernizing legacy systems

Modernization is not necessarily about replacing these applications entirely but rather about upgrading them and refocusing them to meet current needs and standards.

Some of the main benefits are: 

  • Easier management and maintenance, reducing dependence on IT.
  • Improved automation and greater efficiency.
  • Improved data management.
  • Increased scalability.
  • Improved application performance and speed.
  • More agility in meeting changing customer needs.

Key technologies for modernizing legacy applications

In the process of application modernization, several key technologies come into play: 

  • Cloud: leaping to the cloud is one of the main approaches to modernizing applications. It is a technology that offers numerous advantages, such as scalability, agility, and lower costs.
  • Containers and Kubernetes: they facilitate the movement of application packages to improve their management and automate processes. They also allow architectures based on microservices to be built.
  • Microservices: Most legacy applications are monolithic, i.e., self-contained at a single level. A microservices approach emphasizes API-linked services, allowing the best solutions to be chosen and changed to meet new expectations or scale.
  • DevOps: focuses on cross-team collaboration, emphasizing automation and continuous delivery, making it easy to update applications quickly and easily.

Legacy System Modernization approaches

While agility has always been a priority in IT, many legacy systems are critical to some business operations, so it is crucial to examine the ongoing cost of maintaining these legacy systems against the benefits of application modernization.

The process of modernizing legacy systems goes through a process of evaluation to determine the best approach to address it.  

Evaluating legacy systems

There are six main drivers for modernizing legacy applications, which stem from the problems or impediments that the application or system has created as a result of its technology, architecture, or functionality.

The first three drivers come from the business perspective, such as business fit, value, and agility. If applications do not meet new digital requirements or lack the agility to keep pace with demand, they need to be modernized to provide greater business value and not pose a risk.

The remaining three drivers are from the IT perspective and involve cost, complexity, and risk. If the cost is too high, the technology is too complex, or compliance and support may be compromised, it is time to modernize systems. 

Defining the problems

Once we have the initial assessment, it is time to refine the issues causing friction among users in more detail.

Understanding what works well and what does not in legacy software will be critical in determining the approach to modernization. 

Evaluating the modernization of applications

Once the possibility of modernizing a legacy application is confirmed and the problem is clearly defined, it is necessary to define how to do it. Seven approaches (“the 7Rs”) can be chosen, ranked from the lowest to the highest level of complexity, as well as the lowest risk or impact: 

  1. Retain or encapsulate: is a technique that reuses legacy application components within a new architecture. The software is encapsulated and accessed via an API, allowing for extended functionality.
  2. Rehosting: application components are taken and moved to another infrastructure with little or no modification to their code, features, or functions. This is usually the fastest way to move an app from a local environment to the cloud.
  3. Re-platforming: this consists of moving the existing code to a new platform, remodelling it, but retaining the current structure, features and functions.
  4. Refactoring: This is the step of optimizing the code and changing its structure to eliminate the part that leads to legacy software problems (libraries, frameworks, obsolete code, etc.).
  5. Re-engineering: this goes hand in hand with the previous step but goes one step further, as the code is significantly altered to change it to a new architecture with better capabilities.
  6. Rebuild: consists of redesigning or rewriting the application component from scratch, but preserving its scope and specifications.
  7. Replace: when a legacy system no longer works for various reasons, the best solution is to remove and replace the old application component, taking into account the new requirements and needs.  

Choose the modernization approach

When choosing between the seven approaches, you should consider options such as workload, architecture, cost, risk, operations, or security.

The weight of each option will depend on the priority you give to each in your business. You will also have to choose between re-architecture, rebuilding, or replacement. The former has medium costs and risks, but the latter two have better results with higher costs and risks. The key, therefore, is to weigh up all the options to help identify to what extent each will have the desired effect with the minimum effort and the greatest positive impact.  

Adopt a pro-change attitude

Legacy software is often monolithic in design, which can be a major block to upgrading applications. In fact, the average lifespan of an application is 6-8 years, but organizations are subject to constant change from the market, consumers, and the economy.

Choosing flexibility and agility to pivot in today’s changing landscape is crucial to ensuring business success and competitiveness.  

Choose the right partner

Often, internal teams may lack the skills to modernize legacy systems, causing many companies to neglect this task as one of their objectives. It requires constant training, and there are usually insufficient resources to make the right decisions when approaching this process.

Having a technology partner is the best solution to maximize time to market and achieve the best results in the short, medium, and long term. 

Optimize and analyse

Transformation is a constantly moving and changing process, so once a project has begun, it is critical to iteratively test and optimize application modifications to ensure no issues with hosting, software licensing, or connectivity to other services or databases during the transition. 

Legacy System Modernization Partner

Once you have made the decision to modernize your legacy applications, the most appropriate approach will depend on the particular problem you are trying to solve. In fact, this will be key to ensuring the success of the process.

At Plain Concepts, we specialize in application modernization through services that accelerate the move to the cloud, as well as supporting you on your journey to a digital enterprise that a modern and evolving infrastructure foundation underpins.

To this end, we provide you with several services that will help you achieve the business goals you were looking for: 

  • Application and database modernisation: our architects will analyse your applications and architecture to ensure they meet your objectives, taking advantage of the benefits of the cloud.
  • Extended and hybrid collaboration model: if you want to have your team on the project but need to acquire the skills, we can create a new team and adopt the best methodology and working practices to take it forward. We will be your partner in leading the project technically.
  • DevOps Assessment: DevOps is the marriage of people, processes, and technology to enable the continuous delivery of value to our end users. This assessment aims to outline improvements that optimize the lifecycle management of your company’s applications.
  • Creating disruptive solutions: we create innovative applications through disruptive technologies, using 3D graphics in business applications or generating new extended reality experiences.


If you want to discover a new meaning in your applications and systems, don’t hesitate to contact us! 

Elena Canorea
Elena Canorea
Communications Lead