Overcoming the Challenges of Legacy Code in Enterprise Retail

Overcoming the Challenges of Legacy Code in Enterprise Retail

Janusz Toczko - Senior Magento Developer
7 minutes read

As an e-commerce developer, I have been part of the industry since its early days, witnessing the birth and evolution of online retail as we know it today.

Throughout my career, I have encountered various codebases that were developed in different technologies and frameworks, some of which have become outdated and complex over time, earning the label of "legacy code".

These legacy systems present unique challenges and complexities, such as a lack of documentation, adherence to coding standards, and accumulated technical debt.

However, I embrace the opportunity to work with legacy code, leveraging my experience and expertise to unravel its intricacies and uncover opportunities for improvement.

Understanding the underlying architecture and business logic allows me to modernize and optimize these codebases in accordance with industry standards and best practices.

With each legacy code project, I contribute to shaping the future of e-commerce development, creating robust and scalable solutions that power the ever-evolving world of online retail.

What is legacy code?

Legacy code refers to existing software systems or codebases that have been in use for a significant period, often developed using outdated technologies, programming languages, or methodologies. It used to be efficient but is now simply unintuitive and hard to use due to the technological developments that have taken place.

Nowadays, it typically presents challenges such as being difficult to understand, modify, and maintain due to a lack of documentation, adherence to coding standards, or the accumulation of technical debt over time.

So, legacy code may have been written by previous developers according to past requirements and demands, but for today's programming conditions, it is no longer as useful as it once was.

Moreover, it poses challenges to developers in terms of:

  • introducing new features,
  • fixing bugs,
  • or adapting to evolving requirements.

Managing legacy code requires careful analysis, refactoring, and modernization efforts to improve its quality, enhance maintainability, and align it with current development practices and industry standards.

However, each legacy code project contributes to shaping the future of e-commerce development, delivering robust and scalable solutions for the ever-evolving world of online retail. Through meticulous analysis, strategic planning, and skillful execution, legacy code can be transformed into a solid foundation for growth.

This process involves identifying areas of improvement, streamlining processes, and leveraging modern technologies and practices. The result is a codebase that not only meets industry standards but also enables agility, scalability, and enhanced customer experiences.

Common characteristics of legacy code

Legacy code is a complex problem that extends beyond programming challenges and encompasses various aspects of software development, including DevOps and UI/UX.

When dealing with legacy code, developers not only face the intricacies of outdated programming languages, frameworks, and coding practices but also encounter challenges in infrastructure, deployment, and user interface/experience.

It is a multidimensional problem that requires a holistic approach to address the technical, operational, and user-centric aspects.

The following are some of the common characteristics of legacy code:

  • Outdated versions of programming languages, frameworks, or libraries
  • Lack of adherence to coding standards and best practices
  • Monolithic architecture with tight coupling and low modularity
  • Insufficient or inconsistent documentation
  • Limited test coverage or absence of automated tests
  • Use of deprecated functions or features
  • Legacy infrastructure and deployment practices
  • Manual and time-consuming deployment processes
  • Lack of continuous integration and continuous delivery (CI/CD) pipelines
  • Limited monitoring and logging capabilities
  • Inefficient resource allocation and scaling strategies

Recognizing the wide-ranging impact of legacy code and considering these characteristics, developers can better navigate the complexities and devise comprehensive strategies to refactor, modernize, and optimize both the codebase and the supporting infrastructure, ensuring a seamless user experience and efficient development processes.

How to deal with legacy code: best practices

#1 Refactoring is the way to go

Getting involved in legacy code development and making tweaks often leads to a realization of the need for major refactoring. Legacy code, by nature, tends to have accumulated technical debt, outdated practices, and architectural limitations.

As you delve into the codebase and make adjustments, you may encounter issues such as:

  • poor code structure,
  • tangled dependencies,
  • and lack of scalability.

When this happens, refactoring is necessary to improve the code's quality, maintainability, and extensibility. This involves:

👉 restructuring the codebase,

👉 removing duplicates,

👉 decoupling dependencies,

👉 implementing modern coding practices and design patterns.

Refactoring helps eliminate technical debt, enhances code readability, and paves the way for easier maintenance and future enhancements.

#2 Bet on migration

Sometimes, the scale or complexity of the legacy codebase may require considering a migration to a different platform, framework, or architecture.

Migration allows for a new start, leveraging modern technologies and best practices to overcome the limitations of the legacy system. This process involves carefully analyzing the existing functionality, designing a migration plan, and gradually transitioning the code and data to the new platform.

Both major refactoring and migration efforts require:

  • careful planning,
  • resource allocation,
  • and thorough testing to ensure a successful outcome.

When considering whether to undertake a major refactoring or migration process, it is vital to weigh the benefits, risks, and budgetary implications.

#3 What about total revolution

In some cases, the most effective approach to handling legacy code is to start fresh and design the system from scratch. That’s because, after years of development, there may be unnecessary or convoluted parts of the code.

Designing from scratch allows developers to leverage their experience, precisely identify what is needed, and create a more streamlined and efficient solution. It also:

  • provides an opportunity to remove obsolete code,
  • incorporate new functionalities,
  • and improve the overall system based on lessons learned.

However, the decision to start from scratch should consider factors such as time, resources, and potential disruptions to ongoing operations. It is a strategic balance between the benefits of a fresh start and the practicalities of the project.

#4 Identify the unique parts of the codebase

It's not uncommon for custom-written code, extensions, and modules to be added to e-commerce stores, which eventually become a part of the out-of-the-box product. This can lead to situations where a significant portion of the software is no longer available without special effort. Or the once-customized features have become standard features now.

This can create challenges for developers who need to work with legacy code. Therefore, it is good to identify which parts of the codebase are truly unique and which ones have been integrated into the product's standard features.

It's also crucial to recognize how these customizations were implemented, as they may require special consideration when migrating to a newer version or platform. Ultimately, understanding the customizations and how they interact with the existing codebase is key to effectively managing legacy code.

You should also carefully evaluate the benefits and risks of preserving or removing these customizations. Consider many factors, for example, the complexity of the code, maintenance costs, and potential conflicts with future updates or integrations

#5 Update the code bit after bit instead of full range refactor

In some cases, retailers may wish to update only a few specific components of their e-commerce system while leaving the rest of the codebase unchanged. This selective approach to updating legacy code allows them to prioritize their resources and focus on enhancing the most critical or revenue-generating aspects of their online store.

Thanks to updating isolated features, merchants can achieve many results, including:

  • addressing specific pain points,
  • improving the user experience,
  • introducing new functionalities,
  • or staying aligned with changing market trends.

All without undergoing a full-scale system overhaul.

Such an approach offers the advantage of utilizing available resources efficiently and achieving quick wins through delivering tangible improvements to key areas of their business.

💡 However, it is worth considering the potential impact of selectively updating features within a larger legacy codebase.

Merchants should be aware that selectively updating features may introduce discrepancies in terms of user interface, performance, or overall system coherence. It is, therefore, crucial to ensure a seamless and consistent user experience across the entire e-commerce platform with planning, monitoring, and maintaining a balance between updated and legacy features.

With selective feature updates, merchants can prioritize improvements based on their unique business needs, available resources, and customer demands.

This approach offers a more targeted and cost-effective way to modernize their e-commerce system while minimizing disruption to the overall functionality and user experience. And with proper planning, execution, and ongoing maintenance, retailers can achieve a harmonious blend of updated features and legacy components, resulting in a robust and successful e-commerce solution.

#6 Take advantage of TDD

In the face of vulnerabilities and challenges posed by legacy code, harnessing the power of test-driven development (TDD) becomes essential.

It offers valuable benefits when it comes to effectively managing and improving legacy codebases. Through the use of tests before making any changes, developers gain confidence in tackling vulnerabilities while maintaining the desired functionality.

Let's explore how TDD can be a valuable tool in addressing the complexities of legacy code.

TDD acts as a safety net, catching regressions and unintended side effects during refactoring. It promotes modularization through breaking the code into testable units, aiding the understanding and identification of areas for improvement. Tests serve as documentation, clarifying code behavior in the absence of comprehensive documentation.

With TDD, future code maintenance and refactoring become easier, ensuring ongoing stability and improving the quality of the code.

#7 Introduce a standalone frontend

When the primary focus is on improving the look and frontend experience of an e-commerce system, one option is to introduce a standalone frontend that communicates with the existing legacy API.

This approach allows for a two-stage process:

1️⃣ Implementing the new frontend to enhance the user interface,

2️⃣ Gradually updating the backend environment while the new frontend remains operational.

As a result of decoupling the frontend from the backend, developers can independently work on improving the user interface and user experience without disrupting the existing backend functionality.

The standalone frontend can interact with the legacy API, retrieving and displaying data to users while providing an updated and modernized frontend experience. Meanwhile, in the background, the legacy backend environment can be updated, refactored, or replaced with a new system that aligns with current technologies and best practices.

This process is related to many advantages:

  • It can be carried out incrementally, ensuring compatibility with the existing frontend and minimizing the risk of disruptions.
  • It mitigates the risks associated with a complete system overhaul.
  • It provides flexibility in upgrading the backend infrastructure at a pace that suits the business requirements.
  • It also allows for parallel development efforts and reduces the impact on ongoing operations

If the updated backend environment is ready, the switch can be made from the legacy API to the new backend seamlessly without impacting the frontend experience for users.

Proper planning, coordination, and thorough testing are essential for the success of this two-stage process. Developers must ensure the compatibility between the standalone frontend and the legacy API, as well as plan for data migration and potential integration challenges.

Thanks to adopting a two-stage process with a standalone frontend and gradual backend updates, merchants can deliver an improved user experience while ensuring a smooth and controlled transition to a modernized system.

We’re living in a dream, but who’s the dreamer?

For me personally, immersing myself in legacy code evokes a nostalgic journey to the past. It resembles revisiting cherished childhood toys, such as Legos, where I once designed and coded the initial software that now requires my attention. There exists a sentimental bond with the code, as it represents a substantial segment of my professional journey. Moreover, this sentiment extends not only to our own code but also to the code crafted by other companies.

In the present era, where AI pervades our lives, and virtual reality (VR) environments have become our workspace, it's almost like living in a dream.

I find it fascinating how modern integrated development environments (IDEs) highlight every potential issue or problem that went unnoticed during the original development phase. It serves as a reminder of the progress we've made in technology and the vast improvements in code analysis and debugging tools.

Working in VR environments adds an extra layer of immersion and engagement to the process. It's an exciting and futuristic way to interact with the codebase as if stepping into a virtual world where the past and present merge. The AI-driven features of modern IDEs provide invaluable assistance, helping to uncover hidden complexities and pinpoint areas that require attention, ultimately enhancing the quality and efficiency of the development process.

Reflecting on the journey from the past to the present, it's remarkable to witness how far we've come. The advancements in technology and the evolution of development tools have transformed the way we approach and solve problems. While the sentimental value of revisiting legacy code remains, the integration of AI and VR in our work environments has revolutionized the way we navigate and address the challenges of the past, making the development experience even more immersive and exciting.


Whether you want to upgrade your current business applications to work more efficiently or rather migrate to an entirely new platform, we’ll know just how to make the modernization process as straightforward as possible.

If you are thinking about updating your aging system, get in touch and we’ll schedule a meeting to discuss what modernization options would best suit your business.

On-demand webinar: Moving Forward From Legacy Systems

We’ll walk you through how to think about an upgrade, refactor, or migration project to your codebase. By the end of this webinar, you’ll have a step-by-step plan to move away from the legacy system.

moving forward from legacy systems - webinar

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