Legacy Application Modernization: Key Steps and Best Practices

At Artkai, we help many companies modernize and adapt their digital products to new technological requirements and regulations. Every year about 15-20 products of various complexity go through our modernization process. This opens up new opportunities for our business clients to develop and build high-end products.

This article is a complete overview of our practical experience with the best modernization approaches. Based on real successful cases, such as mobile banking and a communication platform for hospitals, we will tell you all about the benefits of modernization, the specificities and effectiveness of this process, and the pitfalls that can be avoided.

Proven approach to legacy app modernization 

We are focused on creating and maintaining an effective process for modernizing legacy systems while minimizing risks. Below, we will look at the main steps of our modernization methodology, each ensuring quality and compliance with business objectives.

Step 1: In-depth research

Modernizing legacy applications doesn't start with coding — it starts with understanding and building the special strategy. An in-depth research is a fundamental step that helps you develop a holistic view of why modernization is needed, what business value it can deliver, and what opportunities can be realized. This phase involves reviewing performance metrics, conducting market research, performing user experience assessments, and technical audits to remove superficial assumptions and move toward strategically sound decisions.

As a result of this stage, the team receives a strategic map with clearly defined drivers, barriers, architectural limitations, and potential areas of improvement, and the client gets documentation with a modernization action plan and the course of future processes. This analysis is the starting point for forming a sound technical strategy that combines business needs, user expectations, and the realities of technological implementation. This is the necessary basis for our team, and now let's take a closer look at what it looks like in practice. 

Mobile banking case

A bank operating in several European markets approached us requesting a modernization of their mobile app. The reasons for this request were critical factors:

As part of the in-depth research phase, we conducted a comprehensive audit in close cooperation with the bank's technical team. Our area of ​​​​responsibility included an analysis of the current technical stack, an assessment of UX/UI and client-side performance.

The set of tasks that were set within the modernization

Deliverables for the client

In-depth research as part of the mobile banking modernization allowed us to form a technically sound product development strategy, taking into account regulatory requirements, security standards, multinational scale, and marketing needs. Thanks to this, the bank received a clear vision of architectural changes and tools for optimizing costs and improving the quality of the user experience. Let's look at the in-depth research stage in our next case.

Healthcare communication platform provider case 

We were approached by a client—a large network of medical institutions that is developing its own internal platform for communication between doctors, nurses, administration, and patients. The network of clinics' internal communication system included three similar-in-purpose but different-in-implementation products that were developed in parallel, with different logic, stack, and functionality.

The solutions were written in Visual Basic and C++, partially rewritten in C# on the .NET Framework, and supported by different teams or completely unsupported. Due to the lack of a centralized approach to architecture, none of the systems scaled properly, and further modernization required excessive effort and costs.

What we found

We conducted an in-depth analysis of existing systems and identified several critical challenges:

The system generally did not support key functionalities considered standard for modern communication platforms in the healthcare sector, including real-time stability on different devices, secure message routing, and flexible integration with medical information systems.

Formulated tasks

During an in-depth research we helped the client not only understand the scope of the problem but also outline ways to overcome the barriers holding back the development of the communication platform at a strategic level. 

Step 2: Selecting approach

After completing the in-depth research stage, we form a specific modernization strategy that considers the level of accepted risk, technical limitations and architectural capabilities, the capabilities of the existing infrastructure, and the client's expectations regarding timing, budget, and scalability.

Note that a combination of approaches such as encapsulation, rehosting, refactoring, etc. gives the best result. Combining several strategies allowed us to preserve a stable part of the system with the implementation of new systems and adapt to the specifics of the business. So, let's consider how it looked based on our cases.

Mobile banking case

In the case of the banking application, we chose a combined approach, which included:

Healthcare communication platform provider case

In this case, we chose a сombination of strategies.

This approach allowed us to avoid large expenses for the complete replacement of the system, preserve critical logic, and set the basis for stable technical development. The approach to modernization is never universal, it is formed individually based on fundamental limitations, risks, and priorities. In both cases — in banking and the healthcare field — the combination of strategies provided us with the ability to achieve high efficiency, and we will show how in the next step.

Step 3: Product modernization

The final, but no less critical, stage is when software architects, developers, DevOps engineers, and designers work together to implement a complete application modernization solution.

Healthcare communication platform provider case

We have moved on to the full implementation of updated solutions for the hospital platform. New software modules were developed and implemented, testing was conducted, and staff training was organized on the use and installation of updated products. All updated systems were successfully launched in the clinics and are fully used in daily operations.

Technology stack used: React, .NET, Docker, Kubernetes, AWS, third-party APIs.

Outcomes

Mobile banking case

The updated mobile app was released for several countries, considering local regulatory requirements. The team continues to release new versions every few months for new countries and supports already-launched versions. A flexible content management system was also implemented, which allows marketing teams to edit content without involving developers.

At the same time, our team faced limitations, as some features, including KYC and onboarding, could not be tested in a staging environment. For this, a limited production testing phase with real users and transactions was organized. The project required close interaction with several teams simultaneously to coordinate all technical and business processes. 

Technology stack used: React Native, Node.js, PostgreSQL, Redis, AWS.

Outcomes

Experience shows that even complex legacy products can be highly efficient after a successful and comprehensive app modernization. 

Although the structure remains the same, the approach must be adapted to the project context, as the product has specific needs and the client has unique requirements. This means that the strategy for legacy app modernization will be different. 

In the next section, we'll share how to choose the right modernization strategy depending on the technical state, business goals, and timeframe. 

Modernization Cost

Businesses that decide to modernize outdated systems often do not fully understand how much it can cost. Our experience has given us a solid basis for preparing an approximate cost estimate, and we are ready to explain in detail how the cost is formed and what it depends on.

The final price depends on many factors, such as the project's goals and requirements, the complexity of the current architecture, the scope of changes, the level of technical debt, and the required depth of integrations.

At Artkai, we divide the duration and cost of modernization into several main categories so that we will show this in examples with numbers.

*Please note that the above cost is approximate and may vary. Let's see what can affect the price of application modernization.

The final cost of application modernization is a derivative of risks, expected scale, and business value. Therefore, the budget can increase significantly for legal architecture and the introduction of new legal and security regulations.

However, timely identifying these factors through a deep audit will help avoid unexpected costs and create a strategically practical product modernization roadmap.

So, once the strategy is defined and the costs are estimated, the next logical step is to evaluate the effectiveness of the application modernization. In the next section, we will show what you can expect from application modernization's technical and business side at the finish line.

What to expect from legacy app modernization

As you have seen in our case studies, modernization can significantly change the functioning of digital products and affect the business and its scaling. To further emphasize its strategic importance, we have compiled the main benefits that any business can receive after a well-planned and implemented application modernization. 

Technical Debt Optimization

Modernization can significantly reduce technical debt, and here are some key indicators:

The business side of optimizing technical debt is manifested in the company's reduced dependence on individual specialists, lower support costs, and faster changes and releases.

Feature Agility

One of the most relevant benefits of modernization is that it allows you to scale the product without redesigning the foundation. The technical side is revealed by:

Business value will be realized in a faster response to market changes and regulations, which will allow for faster launches of new features, reduced TTM, and improved user experience, which will be reflected in an increase in most indicators.

Enhanced customer experience

Outdated products often fail to meet user expectations due to inconvenient interface elements or slow operation and crashes. Modernization eliminates these weaknesses, allowing you to update the product and making it more comfortable and attractive. From the technical side, it looks like this:

Business results are confirmed by NPS, retention rate, and an increase in the number of interactions, which leads to an increased frequency of purchases within the application.

Improved security

Old applications have many more vulnerabilities, such as weak or absent authentication, absent encryption, and much more, which can lead to the leakage of critical information. Modernization of security issues should be a priority, and the technical side looks like this:

This will reduce the number of incidents related to fines and downtime for businesses and improve their reputation and compliance with generally accepted requirements and standards.

Modernizing legacy applications is a strategic step in updating the business to meet market needs and increase profits. Note that this should be an investment in the sustainability of your services and products, which will guarantee a reputation for many years.

Final thoughts

Modernizing an outdated application is not just another technical update but a successful strategic investment in your digital product. The right approach guarantees long-term business value, from reducing the risks of downtime and minimizing technical debt to increasing system performance, optimizing architecture, and improving the end-user experience.

This article contains proven strategies and approaches for working with our clients. We hope the practical ideas and approaches will help you avoid mistakes and implement the next steps.

If you are looking for a reliable partner to guide and help you modernize your legacy application, let's discuss it. Contact us, and we will contribute to your technological progress.