what is a legacy system and how to modernize it

Key Takeaways

  • Legacy system modernization can significantly enhance organizational efficiency.
  • By updating outdated systems with the latest technologies, companies can improve their workflows and reduce downtime costs.
  • Modernizing legacy systems can drastically improve security protocols and risk. mitigation.
  • In 2023, over 50% of surveyed companies identified enhancing security and efficiency as key drivers for the modernization of their legacy applications and data.

In a mostly cloud-based, digital-first business world, legacy systems often play the role of the silent yet influential anchor. The broad legacy software definition embodies the foundational software and hardware infrastructures upon which a business’ daily functions rely.

Being once indispensable tools to perform business-centric operations, they are rather maintained than adapted or modernized to address modern operational needs. As we need to be responsive and agile, this anchor can also act as a drag, stopping growth and impeding movement.

By modernizing legacy systems, we have witnessed businesses open up a brand-new page of success by replacing outdated software. In this post, we’re exploring the legacy systems’ meaning in the business context.

Find out how legacy applications cause disruptions, when to modernize your systems, and how to approach the shift right.

What is a Legacy System?

A legacy system is a platform, application, or technology that once was on the cutting edge but is now outdated. It can be considered dated either because it has been replaced by a more current iteration or requires significant work to maintain its compatibility with newer systems.

Legacy software, typically older than one decade, can be defined by its inability to handle the tasks required by the organization adeptly. If the cost to keep software running has become prohibitive, it’s also a sign of disadvantageous business operation.

So, what does “legacy” mean in software? The perception of a system as a “legacy” depends on specific business objectives. The state of technology at the time of implementation also identifies the system as outdated.

Why are Legacy Systems Still Used?

Legacy systems persist due to factors such as the high cost and complexity of replacement, as well as their integral role in critical business functions. Customizations and the lack of in-house expertise further contribute to the reluctance to upgrade.

Industries with stringent regulations, like banking or healthcare, may resist change to maintain compliance. Interoperability challenges, risk aversion, and a perception of stability in existing systems also contribute to their continued use. Long life cycles, incremental modernization, and the fear of disrupting integrated ecosystems are additional factors influencing the decision to stick with legacy systems.

At the same time, more and more businesses plan to start the upgrade journey.

legacy systems meaning and relevant statistics

More than 50% of surveyed companies cite boosting security and efficiency as primary motivators for modernizing their legacy and data applications in 2023. Nearly 50% of respondents also mention cost reduction, improved integration with modern technologies, and increased agility and flexibility as key drivers.

While regulatory compliance is the least popular driver, around 20% of surveyed companies still consider it a significant factor.

8 Signs of a Legacy System Slowing Down Your Business

legacy systems definition and signs you need to modernize your software

Modernization and software reengineering are not simply a matter of following trends but staying competitive and secure. Here are the eight most evident signs that define a legacy system and show that your software is ripe for an upgrade.

Outdated Technology

When your technology can’t keep up with the latest developments, it’s a clear sign that you’re using a legacy system. This translates to slower performance, restricted functionalities, and an inability to keep pace with customer demands.

High Maintenance Costs

Is your IT budget shifting more towards maintaining old software rather than creating business value? Legacy software often incurs high maintenance costs due to the scarcity of expertise, unavailability of parts, and the need for constant patches and updates to prevent security and privacy breaches or system failures.

Poor Performance

If your system routinely crashes, often requires rebooting, or slows down significantly under regular usage, it’s a sure sign that your legacy system hinders productivity.

Security Vulnerabilities

Out-of-date software typically means out-of-date security, leaving your system vulnerable to exploitation by cybercriminals. Without the latest cyber practices, legacy systems become significant security liabilities.

Limited Scalability and Integration

Is your business growing or looking to expand its capabilities? A legacy system’s rigidity can be a significant roadblock when it comes to integrating with modern applications or scaling your operations.

Compliance Risks

Staying compliant with industry and data regulations is a non-negotiable responsibility for any business. However, legacy systems often lack the features or updates necessary to keep up with the latest compliance requirements, exposing your organization to unnecessary risks.

User Frustration

Would an employee rather use their devices or a complicated, slow system that requires multiple steps to complete a task? User frustration can be the canary in the coal mine for deeper-rooted performance issues.

Business Inefficiencies

Lastly, legacy systems can cause bottlenecks and inefficiencies throughout your business processes. This could be outdated reporting tools, over-reliance on manual data entry, or inadequate workflow support. Here, some low-code automation features could figure things out, enhancing your current functionalities with ease.

How to Overcome Legacy System Challenges

legacy software challenges and how to deal with them

Although legacy software represents a company’s historical development, it is impossible to ignore the emerging issues it presents. Strategies to mitigate legacy system problems require careful, considered planning, and here are some relevant solutions for you to consider.

1. Legacy System Modernization

Modernization aims to revamp and enhance the existing legacy system, rejuvenating it with the latest technological advancements. Usually delegated to outsourcing or outstaffing providers, the process implies infusing new protocols, technologies, and features into old software.


  • Legacy software updates maintain the key functions that the organization relies on. There’s no need to start the development from the beginning.
  • Since it doesn’t require total redevelopment, it’s likely to bring fewer workflow disruptions.
  • Transforms the system into a more flexible, adaptable, and scalable model for future growth.


  • Potentially costly and labor-intensive operation requiring a considerable investment.
  • It won’t necessarily rectify fundamental issues if the base architecture is obsolete or inherently flawed.

2. Data Migration

A crucial aspect of modernizing legacy software is data migration, which involves a comprehensive switch from legacy systems to newer technologies. This approach is designed to ensure successful and smooth data transit from old to new workflows. The crucial steps of successful migration include:

  • Data transfer, which relocates all the essential data from the old to the new system. This sensitive process guarantees nothing is damaged or misplaced during the migration and transition.
  • Period of overlap, where you run both old and new systems simultaneously for a certain period. This gives time to rectify any issues and certify the new configuration won’t interrupt routine business procedures.
  • Employee training is crucial for smooth company-wide adaptation. Your teams should be thoroughly trained and familiar with the new system.

3. Integration with Modern Systems

Rather than altogether abandoning legacy applications, integration attempts to harmonize them with the newly adopted solutions by using middleware or creating custom APIs:

  • Middleware serves as a translator between the old and new systems. It connects the gap so both systems can communicate and operate in concert.
  • Custom APIs (application programming interfaces) can be designed to facilitate interaction between different software platforms. This allows companies to retain important legacy functions and gain from the new, trending features.

4. Gradual Retirement

For companies not yet ready to abandon their old systems completely, gradual retirement offers a less drastic transition approach. With this solution, the legacy software isn’t turned off abruptly. Instead, it’s gradually phased out as the new system slowly assumes its functions.

This approach minimizes operational disruptions and provides the organization with ample time to adjust.

What Are Legacy Systems Modernization Benefits?

what is legacy software modernization and what are its benefits

System modernization might seem daunting, but the benefits far outweigh the costs. In this section, we’ll explore five key areas where updating your legacy systems can profoundly impact your business.

Enhanced Performance and Reliability

New systems and modernization trends are designed with the latest technologies, meaning they can easily handle the demands of today’s business environment. They’re also far less likely to suffer from regular breakdowns, keeping critical business processes running smoothly.

Improved Security Measures

A modern system comes equipped with the latest security features, helping to protect your business from the constantly evolving threats. With cloud migrations, updates are also more regular and less disruptive, keeping your system secure without impeding workflow.

Cost Savings and Efficiency Gains

The initial investment in modernizing your system is usually recouped through long-term savings in operating costs. New systems are more efficient in using resources, such as power and IT staff time, as well as in the money saved by preventing security breaches.

Scalability and Flexibility

One of the key advantages of modern systems is their ability to scale with your business. Whether you’re experiencing rapid growth or simply need extra functionalities, a modern system will provide the flexibility you need.

Compliance and Regulatory Adherence

With new regulations constantly being introduced, the agility to keep up with compliance requirements is critical for any business. Modern systems are better designed to adapt to these changes, ensuring you’re always on the right side of the law.

Legacy System Modernization by Acropolium

At Acropolium, we’ve been assigning talented DevOps and software engineers to clients’ and partners’ software projects for 10+ years. Our teams delivered modernization services and implemented cutting-edge strategies to help businesses operate with relevant software and remain competitive.

AI Contracting Software Modernization

Our client, an international legal company, requested a software upgrade to navigate within the ever-evolving standards for contract processing. The initial system couldn’t handle modern contracts, so the company required enhanced precision and compliance in contract analysis.

Additionally, the client needed a streamlined and effective workflow where a solution would integrate seamlessly with existing legal and document management systems.


To address the client’s challenges, our dedicated team:

  • Modernized the AI contract analysis tool for better scalability, functionality, and UX.
  • Redesigned UI, prioritizing intuitiveness and optimal UX across devices.
  • Conducted user interviews and surveys to understand pain points and requirements.
  • Enhanced visualization of analysis results with charts, graphs, etc.
  • Implemented interactive reporting features for in-depth insights.
  • Assessed existing legal and document management systems for seamless integration.
  • Utilized robust APIs for secure and efficient system connections.
  • Integrated the platform with financial systems and CRM tools for holistic contract analysis.
  • Encouraged cross-functional collaboration between departments.
  • Implemented strict security protocols for data integrity and confidentiality.


  • The client experienced contract review times cut by 75%.
  • The solution boosted accuracy in contract analysis, promoting improved risk control and compliance.
  • System modernization lowered operational expenses and lessened dependency on outside legal services.

Legacy ERP System Modernization

An oilfield service company struggled with outdated enterprise resource planning (ERP) systems plagued with obsolete technology, systemic errors, and complex processes. These issues stemmed from legacy coding practices and a mixed tech stack, leading to system failures and workflow inefficiencies.

Also, old-fashioned user interfaces have complicated workflows, reducing efficiency and negatively affecting the employee experience.


In response to these challenges, we initiated a comprehensive reengineering process:

  • First, we focused on updating the technology stack to enhance the ERP system’s reliability and security. This led to fewer bug reports, improved system performance, and streamlined employee tasks.
  • Our web development team revamped the client’s UI/UX designs to create a more user-friendly interface with logical task workflows.
  • We incorporated new Azure cloud services to alleviate processing loads and redistribute maintenance tasks.
  • Acropolium also implemented cloud resource optimization and autoscaling of services, ensuring cost-effectiveness while enabling the platform to handle demand surges.
  • We introduced the Agile method to the client, who was accustomed to the linear Waterfall approach.

Final thoughts

Legacy system modernization is an investment in the future of your business. By recognizing the signs that your system is holding you back and understanding the benefits of an update, you can take the first steps toward a more efficient, secure, and competitive IT environment.

Although the change may pose some challenges, the rewards are well worth the effort. Your business deserves an IT infrastructure that empowers it to grow and innovate, and that starts with leaving the legacies of old in the past where they belong.

What is a legacy system for you, considering the functions it performs and the cost it takes to maintain? That is the question you have to weigh thoroughly to evaluate the actual value of your existing system. Whether full or partial modernization, from hospitality systems to logistics software upgrades, our expertise is here to translate to your success.

Acropolium will be there for you to provide a quality assessment of your business tools, suggesting suitable options for making them future-proof. Contact us — we offer many flexible forms of cooperation, including subscription-based services where your budget is prioritized.

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