How To Approach Legacy System Modernization: From Theory to Practice

Fact: 74% of companies that start modernizing their legacy software systems fail to complete it. The Mainframe Modernization Business Barometer report states that the lack of success or progress in modernization projects often happens because of the disconnect between business and technical teams. 

The reasons for that disconnect range from unspoken expectations and misaligned goals to insufficient communication and differing priorities. All these can lead to misunderstandings about project scope, inadequate resource allocation, and poor progress. 

Ensuring both teams are aligned and working towards a common objective is crucial for the success of any modernization effort. Evaluating the state of your current legacy system and identifying and communicating future needs can help bridge the gap between business and technical teams, increasing the likelihood of choosing the right modernization strategy and its successful implementation.

In this article, Leobit shares our hands-on experience and best practices for assessing and modernizing legacy software, illustrated with real-life examples of our modernization projects.

Modernizing business-critical software without causing operational disruptions or data leakage requires a thorough assessment of its current state.

At Leobit, we suggest starting by assessing the state of the legacy software to help businesses ensure successful modernization and a smooth transition to the updated system. The legacy system assessment framework involves several steps to identify the software’s capabilities and limitations. This helps us understand potential areas for improvement to ensure the software can align with current and future business needs.

The first and foundational step in assessing legacy systems involves thoroughly examining the software’s programming languages, frameworks, databases, and other tools. This process aims to:

• Understand the relevance or obsolescence of the current tech stack
• Identify technical debt and unsupported technologies that may pose risks or limitations
• Decide whether the tech stack can handle the upcoming changes

Based on the evaluation, our tech experts can provide guidance and suggest modern technologies to replace or enhance the current stack for better performance, security, and maintainability.

During the architecture audit, our tech team goes beyond examining the system’s basic structure (like modularity, scalability, and integration capabilities). We dive deeper to understand its non-functional qualities, which can be crucial for future success. This involves two key steps:

• Quality attributes workshops. We facilitate collaborative workshops to identify and prioritize the system’s non-functional requirements. These workshops leverage the ISO/IEC 25010 standard, which defines a comprehensive set of quality attributes like scalability, security, maintainability, and performance. Engaging stakeholders in these workshops gives us a well-rounded perspective on the system’s essential qualities.
• Architectural requirements and modernization roadmap. Based on the previously identified quality attributes, we define architectural significant driving requirements (ASDRs). These ASDRs represent the high-level architectural principles that must be considered during modernization to ensure the system meets its non-functional goals. From the ASDRs, we create a step-by-step plan outlining the specific architectural improvements and modernization recommendations. This plan prioritizes actions based on severity and impact, ensuring a smooth and targeted modernization process.

Our audit combines traditional architectural analysis with a focus on non-functional quality attributes, providing a more holistic view of the system’s strengths and weaknesses. It helps:

• Determine whether the current architecture is robust enough to support future enhancements or integrations
• Identify whether the architecture can scale with the business’s growth and evolving needs
• Pinpoint architectural flaws or bottlenecks that could hinder performance or flexibility.

The audit also reveals how future changes might impact the entire product and identifies elements that need modernization.

Before commencing the modernization journey, we thoroughly review the hardware and software environment in which the legacy system operates, including servers, databases, networks, and cloud services. The goal is to determine whether the current infrastructure supports our customer’s modernization goals. The review helps us to:

• Highlight inefficiencies in resource usage and potential areas for cost reduction
• Assesses the feasibility and benefits of migrating to cloud infrastructure
• Ensure the infrastructure can handle failures and recover quickly, maintaining business continuity

Sometimes, when migration is needed, we suggest specific strategies or solutions to facilitate the transition.

Legacy software may often have an excessive codebase that requires regular reviews and refactoring to function well. Without proper maintenance, the software tends to “rot,” becoming faulty and unusable. Our code review process involves examining the software’s source code to:

• Identifies bugs, code smells, and areas where the code could be improved for readability and maintainability.
• Evaluates how easily the code can be understood, modified, and extended
• Highlights areas where code efficiency can be improved

Addressing these aspects as part of a global legacy modernization strategy ensures that the software remains robust, efficient, and adaptable to future needs.

Security is paramount when modernizing legacy systems to protect sensitive data and ensure compliance with regulatory requirements. Leobit holds an ISO 27001:2022 certification and knows how to build GDPR, CCPA, and OWASP-compliant software. After auditing your legacy software, we provide recommendations for improving security measures to safeguard your system and data and prevent data leakage or loss during and after modernization.

Legacy software may also have outdated UI/UX design, making the system unintuitive and difficult to use, especially when new features are added. Additionally, older software may not be accessible to all users, including those with disabilities. That’s why our UI/UX experts thoroughly evaluate the software’s look and feel and provide recommendations to ensure the software is user-friendly and accessible to everyone.

This step involves testing the software under various conditions to evaluate its performance. This includes, but is not limited to:

• Load testing to see how the software handles high volumes of users or data
• Stress testing to assess software’s performance under extreme conditions

The results help us understand how the system will perform as usage scales and identify performance bottlenecks that must be addressed to improve speed and efficiency.  This ensures that when we modernize your legacy software, it can handle future growth without degradation.

An assessment helps us identify critical issues such as time-to-market delays, high maintenance costs, expensive scaling, security vulnerabilities, etc. Understanding the current state of the legacy system and our customers’ pain points helps us choose the right legacy software modernization strategy and tailor it to align with customers’ goals and plans.

Now that you know how we assess legacy software, let’s explore the best practices and valuable lessons we’ve learned when dealing with obsolete systems.

Navigating the complexities of modernization projects effectively requires a strategic approach and a clear understanding of the challenges involved. Having modernized dozens of legacy systems for companies spanning a wide range of industries, Leobit has compiled a list of best practices that can help avoid common roadblocks and build an efficient modernization strategy.

Whether you’re just starting your modernization journey or are already in the midst of one, these insights can help you optimize your approach and achieve successful outcomes.

Modernization is a structured process that begins with establishing a clear vision of the desired end-state architecture. To achieve this, we recommend developing a detailed roadmap outlining the desired outcomes and the steps required to transition from the system’s current state to the envisioned state. This roadmap should Include short-term, medium-term, and long-term goals and key performance indicators (KPIs) to ensure each phase is achievable and measurable.

Validating the feasibility of the modernization plan is essential before fully committing to it. We suggest implementing a proof of concept on a separate feature or module to ensure the envisioned modernization approach works as planned. This helps us identify potential challenges and solutions early in the process.

Prioritizing modularity means designing the new system divided into smaller, independent components or modules, each responsible for a specific functionality. This approach is essential for ensuring the system’s agility, regardless of whether you choose a microservices or monolithic architecture. Just like in microservice architecture, modular monoliths let you prioritize critical components, enabling flexibility, observability, and reduced coupling. As a result, they improve agility and reduce overall system complexity.

However, if you also want to scale and maintain application modules independently, you should opt for a microservice architecture approach.

When modernizing legacy systems, companies can choose between horizontal and vertical modernization.

Horizontal modernization involves migrating an application from outdated technologies to a new tech stack layer by layer, such as rewriting the front end, then the back end, and finally, the database. While this approach can be effective in some cases, it often carries over outdated and inefficient coding practices from the old system into the new one.

Vertical modernization, on the other hand, involves migrating entire features across all layers (backend, frontend, database) cohesively. This approach aims to update technology and rethink and innovate business processes. It reduces the risk of inheriting poor technical decisions and avoids tightly coupling old and new systems. A vertical approach ensures meaningful progress and minimizes layer integration issues, leading to a more efficient and modernized system.

Begin the migration with smaller, less complex, and more isolated services, such as email services, authentication, document management, etc. Successfully migrating these components builds confidence and provides a clear path for handling larger, more interconnected domains.

Ensure each service has its database and communicates with other services asynchronously, preferably through a message bus. It allows different parts of a software application to communicate with each other by sending and receiving messages. This approach reduces tight coupling, promotes isolation, and simplifies scaling. 

We also suggest using an API gateway to manage external interactions and handle cross-cutting concerns like authentication and security.

During the modernization process, you may encounter unexpected challenges, such as wide contracts and frequent inter-service calls, regardless of how well-planned your legacy system replacement strategy is. To address these issues:

• Simplify contracts to include only essential methods
• Introduce locally cached copies of frequently accessed data to reduce service dependencies and improve performance
• Adopt eventual consistency models where feasible to ensure data integrity without compromising efficiency

Addressing these issues proactively will help you minimize potential disruptions and improve the overall outcomes of your modernization efforts.

When defining the new architecture, it’s essential to remain flexible with technology choices. Microservices architecture offers the flexibility to use different technologies and frameworks for various services, for instance, .NET for most modules and Python for Generative AI integration.

When selecting technologies, it’s crucial to ensure they are well-supported and align with your team’s expertise and project requirements. Additionally, to facilitate smooth transitions and platform agnosticism, it’s essential to have containerization and CI/CD pipelines in place to streamline development, testing, and deployment processes.

Despite the clear benefits that modernizing legacy software can bring to businesses, technical teams who are eager to drive innovation often feel resistance from leadership. In fact, the Mainframe Modernization Business Barometer report finds that only 12% of Application and Infrastructure Managers report receiving full funding commitment from leadership for modernization projects. Furthermore, 56% attribute this lack of funding to a fear of change. But why does it happen?

Decision-makers may feel reluctant to upgrade and migrate to newer technologies, viewing such changes as disruptions to conventional work processes. They may often fear that users might find upgrades confusing and struggle to adapt to newer technologies and workflows.

Implementing effective change management strategies that address both the technical and human aspects of the transition can help you overcome the resistance. Here are some steps companies can take to ease that process:

• Communicate the change. Inform your users, whether company employees or customers, about the upcoming software changes. Communicate the reasons behind the changes and the benefits they will bring.
• Roll out gradually. Implement the new system gradually. Start with a pilot group of users, gather feedback to ensure the new system meets their needs, and then roll out the system to larger groups. 
• Provide training and support. Provide comprehensive training and support to help users adapt to the new system. This could include workshops, manuals, usage tips, etc.
• Monitor and optimize. After implementation, continuously monitor the system’s performance and user feedback to optimize and make necessary adjustments.

Such an approach will help you smooth the angles and ensure the optimized software meets users’ needs.

Modernization is a journey that can span the long term, during which your needs and priorities may evolve. Therefore, embracing continuous iteration and improvement is crucial to keeping the modernization effort aligned with your goals and delivering the desired outcomes.

To ensure the success of your legacy modernization strategy, it’s essential to periodically review progress against the roadmap. Be open to feedback and ready to adjust plans based on evolving requirements and insights gained along the way. This flexibility and adaptability will help keep your modernization efforts on track and lead to successful outcomes.

Now that you know the theory, let’s see how it works in practice.

Having helped numerous small and large companies build effective modernization strategies and transform their legacy software, Leobit has some success stories to share. 

Here are several of the latest case studies that highlight our professional approach and expertise.

Our customer, a Canada-based healthcare practice management solution provider, asked us to update their legacy software and build new modules without disrupting their operations. After reviewing the existing software’s source code, our engineering team determined that the company’s growth had outpaced the capabilities of the old EC2 system architecture and required migration to the cloud and enhancements through containerization and automated deployment. 

We started with the architecture update and automated manual software deployment and testing through GitHub Actions. This shift helped us to boost the platform’s performance and streamline future updates.

We also assisted the customer in meeting regulatory compliance by ensuring that patient health information (PHI) was stored locally. Leobit configured the app logs to transfer technical data to a central server while keeping patient info within the country. This made data management and searches more convenient and allowed the customer to obtain licensing from the Canadian government. Additionally, our front-end developers refactored the software to enable smooth PDF rendering and implemented additional features, including appointment scheduling and telehealth functionality.

Our cooperation helped the Canadian healthtech solution provider optimize infrastructure maintenance costs, streamline operations, and increase the number of end-users. Read more about the modernization process in our Healthcare Practice Management Platform case study.

Our client, a leading player in managing investment property wealth through 1031 exchanges in the US, encountered scalability challenges and sought a swift and comprehensive overhaul of their product architecture to unlock growth opportunities. They also aimed to transition their infrastructure to the cloud to reduce costs and enhance their offerings with new features. 

To address these needs, we conducted a thorough assessment and, based on the results, chose a modernization approach and started meticulously restructuring the existing system. Given the client’s emphasis on cost optimization and scalability, we opted to migrate the platform to Azure. This move provided advanced infrastructure management capabilities such as automatic scaling and load balancing, allowing the platform to handle fluctuations in user traffic efficiently.

Following the development of the new architecture, we focused on synchronizing investment offerings and migrating users to the updated platform. To achieve this seamlessly, we developed custom scripts to extract data from the existing database while ensuring an uninterrupted user experience throughout the transition.

As a result of the architecture redesign, our client gained control over a significantly larger volume of transactions, leading to a substantial increase in operational efficiency. Additionally, our ongoing technical partnership contributed to the client’s success, as they got $6 million in Series A funding shortly after the modernization. Find out more about their modernization journey in Real Estate Investment Management Platform case study.

A US-based legal case management solutions provider sought Leobit’s help in legacy software modernization. Initially developed in the 1990s, our client’s software solution was due for an upgrade to enhance speed and user experience by migrating legacy code to modern technologies and incorporating new features. 

Leobit’s primary goal was to transition the codebase from ASP.NET Forms to Angular 11 without causing any disruption to the client’s critical system, which serves the government and legal sectors. To achieve this, our experts rewrote the legacy codebase, module by module, ensuring seamless integration with Angular while enhancing performance using TypeScript.

A crucial aspect of the migration involved integrating a wide range of UI components from the legacy system into the new framework, including forms, buttons, modals, menus, and navigation. By carefully incorporating these UI elements, our development team ensured that the system retained its core features while leveraging the capabilities of the new framework.

While migrating the legacy code to the new framework, our team meticulously evaluated each endpoint to determine the most appropriate approach for handling it within the new Angular framework. For some endpoints, we replaced outdated implementations with new ones, while for others, we replicated them and made necessary adjustments to align with Angular’s framework. This approach enabled us to use the existing backend infrastructure while ensuring compatibility with the new front-end framework.

Discover more insights in our Legal Case Management Platform case study. 

We provide a comprehensive suite of modernization services, including technical software assessment, platform migration, refactoring, and complete redesign and rebuilding from the ground up. With our assistance, your outdated software will undergo a transformation into a future-proof solution that complies with modern security standards and can harness the benefits of emerging technologies and AI transformation.

Our diverse portfolio spans various industries, including fintech, sportstech, logistics, healthcare, real estate, proptech, and more. Clutch has acknowledged our expertise and proficiency, ranking us among the top 1000 global B2B service providers in 2023.

Here’s what our clients say:

Legacy software modernization is a complex process that requires:

• A thorough assessment of the current system state
• A clear outline of the software’s ideal capabilities
• A detailed roadmap to achieve the desired outcomes
• The right modernization strategy

However, unexpected challenges can arise even with a well-planned legacy system modernization strategy. By addressing these issues proactively and adjusting your modernization plan as needed, you can minimize potential disruptions and improve the overall success of your modernization efforts.

Embarking on a software modernization journey can be daunting, especially without a reliable software development partner to guide your efforts. Leobit can be your right hand and help you choose the right legacy system replacement strategy to meet your current and future needs. Contact us to learn more about our experience and ways we can help.