In 2022, financial institutions suffered from multiple breaches, incurring staggering direct costs of $2.19 million. The main cause? The outdated legacy authentication system’s failure to keep up with modern cybersecurity threats. Legacy systems refer to outdated technologies or software that lack modern features and security protocols. Updating such an outdated system would require a legacy application modernization approach.

Updating a legacy system involves conducting a comprehensive assessment to identify areas that require improvement. This may include reviewing the user interface, data architecture, and application performance. Surveys have revealed that 80% of businesses are unable to reach their full digital potential. Modernizing them improves their functionality and compatibility with modern technology. Let's explore the different facets of using legacy applications in more detail.

Challenges and Risks of Maintaining Legacy Applications

But why modernize legacy applications? Legacy applications can be compared to using an abacus - outdated and incompatible with modern tech. But many businesses stick with them because of the overall investment in them.

Upgrading to modern systems through legacy applications modernization is crucial for security and other risks involved. If legacy applications are maintained as they are they can lead to -

1. Increased security risks

Outdated legacy systems often have many security vulnerabilities that can be easily exploited by hackers This leaves your business at risk of data breach violations and other security risks.

2. Inflexible and inefficient

Given the monolithic structure of many legacy applications, they can be rigid and hard to customize. This makes them unable to adjust to your business's growing modern needs. This further adds to your labor costs and slow processing speeds.

3. Incompatible with modern technologies

These systems have limited capabilities to integrate with newer technologies. If your goal is to stay competitive it's imperative to keep up with your competitors’ modern technologies.

4. Higher cost of maintenance

The cost to maintain and license old legacy systems can affect your ROI. As the systems grow older, their costs grow higher. A legacy system update/legacy migration can help you reduce these costs and add to your bottom line in the long run.

5. Compliance risk

It's impossible to update older systems with the new advancements in technology. Unfortunately, this means that you risk penalties or legal action for failing to meet current regulations. This can cause irreparable damage to your finances and reputation.

So, what are the benefits of modernizing legacy applications? With a modern switch, you can troubleshoot all these risks and challenges. A modern application will improve your application's performance, security, and compatibility.

Different Types of Legacy Applications Modernization Options

Still on the fence about modernizing your legacy system? There are different types of approaches to take for a legacy system update/legacy migration. Let’s explore some ideas below to see which one would suit your business best -

1. Rehost

Rehosting is the perfect option when the application works fine, but its hardware or software has grown outdated.


  • Quick
  • Cost-effective
  • Low-risk


  • Limited modernization capabilities
  • Continued maintenance issues
  • Unaddressed security risks

Samsung Electronics migrated its 1.1 billion account users from its on-premises legacy database to Amazon Aurora. The company saved a significant amount of money and completed the process in 18 months.

2. Rearchitecting

Rearchitecting your application is the best option when it needs to be updated. Especially, when you aim to meet modern business requirements.


  • Boosts functionality
  • Improved performance
  • Better scalability


  • Time-consuming
  • Costly
  • High risk of failure

Musio, an AI startup in Singapore needed a more efficient and reliable service that could help run heavy data analytics. They experimented and implemented a re-engineered architecture on Google Cloud Platform’s GKE. The results - the strength of the server allowed them to hold >90% of the CPU load without problems.

3. Rebuilding

Old applications often struggle with modern programming languages and technological advancements. In this case, it is more feasible to conduct a complete overhaul of the application.


  • Improved functionality
  • Modern and robust applications
  • Enhanced flexibility


  • High investment of resources
  • Expensive
  • Potential user pushback

The orthodontic service provider Aligner 4D was rebuilt by RootQuotient. Their goal was to improve its 3D design and scalability. The app now offers a virtual treatment simulation and 3D object handling. It also handles appointment management and payment handling, with a seamless multi-tenant architecture.

4. Replatform

Replatforming involves moving an application to a new platform or version. The migration keeps its existing structure and features intact with minor code changes.


  • Faster cloud migration
  • Lower licensing cost


  • Unaddressed application architecture or design issues
  • Compatibility issues
  • Technical debt carryover

Fluidly re-platformed to Google Cloud to scale up quickly to accommodate its 30,000 clients. The migration helped the fintech startup to scale its services to 50,000 customers seamlessly.

5. Replace

In some cases, the system supporting an application can become too outdated to be rebuilt or re-platformed. In such situations, it may be best to retire the legacy application. You can instead replace it with a new application more suited to modern technological environments.


  • Reduced maintenance costs
  • Better functionality
  • Improved scalability


  • Time-consuming
  • Data migration challenges
  • Possible user pushback

Choosing the Right Legacy Applications Modernization Approach

A list of approaches to legacy migration is great, but how to choose one? The right approach to legacy application transformation would factor in your business goals and requirements. Take the following steps to land on the right modernization approach for your legacy software:

1. Assess your application

A comprehensive assessment can help you decide on the legacy applications modernization approach. Run a SWOT analysis on the architecture, codebase, UI, and model to identify the areas that need improvement.

2. Specify your business goals

Before you go down the application transformation route, define what goals and requirements the application needs to meet. This will help guide your organization's efforts down the right path. It will also help you choose the right modernization approach for the legacy software.

3. Analyze resource availability

Before you jump off the deep end of upgradation, make sure that all your ducks are in a row. Evaluate the budget, available staff, and technological infrastructure available to you to scale up your operations.

4. Compare different modernization approaches

You have already assessed the app system and your business goals. After evaluating your available resources choosing a legacy applications modernization approach becomes easier.

5. Beta test

Each new step in business comes with its risk and rewards. Having analyzed this, you have now chosen and implemented a legacy system update. But before release, it’s always important to test the new infrastructure. Start small and adjust the plan as you go to ensure the approach is going according to plan.

When strategizing and finalizing an approach, ensure that you have the right expert hands leading the initiative. Product engineers at RootQuotient are the right experts for digital solutions such as this. They analyze data and provide insights for the best custom solutions suited to your needs.

Give Up Your Technical Debt With Legacy Modernization

Legacy application modernization can help you minimize costs and improve application security. There are various approaches you can take when working on a legacy system update/legacy migration. Some well-known modernization techniques include rehosting, rearchitecting, and rebuilding.

The key to success lies in assessing the system and determining goals and resources. Partner with the right engineers with expertise in custom software development services to meet your business needs.