All About Legacy Systems [+9 Examples with Lessons Learned]

Dayana Mayfield

Software Development Projects

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Considering that the Internet began in 1983, there are many examples of legacy systems. As technology continues to change, what was efficient just five years ago could be considered legacy today.

To make things more interesting, we've collected legacy system examples that were resolved—or that have yet to be modernized—and considered the lessons learned from them.

What's in this guide:

  • What is a legacy system?

  • Types of legacy systems

  • Legacy system examples

  • How to modernize legacy software

  • Frequently asked questions

What is a legacy system?

The legacy system meaning is any outdated software or hardware that continues to be used by a business or organization. 

Typically, these systems remain in use due to the critical role they play in business operations, the high risk of data migration, and the excessive cost of integration or replacement.

Types of legacy systems

Legacy systems can wreck an organization. Outdated systems can be either customer-facing or for internal business use only.

While there are many different reasons why a system might earn the "legacy" label and need to be modernized, the reasons typically boil down to the following:

  • End of life - The technology used to build the application could be at the end of its rope. Maybe it's a programming language that fell by the wayside (we're looking at you, Haskell). Or maybe it's a programming language that, while efficient for other products, is causing major problems for yours. Or perhaps the technology is at the end of its life in terms of modernity and developer preference.

  • Outdated architecture - The architecture of your data and code can also cause major problems. For example, to modernize their software, Shopify had to move from a monolith to a modular monolith in order to innovate faster.

  • Lack of internal system knowledge - Maybe the people who built the software have left your company, taking their knowledge with them. If you have poor knowledge transfer practices at your company, then this situation is very possible.

  • Lack of internal system skills - You might have newer, younger developers coming in who would rather use modern frameworks than learn whatever language and frameworks your system was built with. Sometimes, rather than upskill your developers in an old language, it's better to modernize the application instead.

  • Scalability - Does that application continuously fail to scale? Can it not handle busy times of the week? Is your user growth inhibited? Scalability is behind a lot of legacy system issues.

  • Challenging to update and innovate - This problem is nearly always present, because other technical legacy system issues cause challenges where innovation is concerned. It might take weeks or months to launch feature updates that should take a matter of days. This could be caused not just by legacy code, but by legacy tooling relating to DevOps.

Because all of these problems are interwoven, companies typically face at least a few of these challenges all at once

9 legacy system examples to learn from

Here are some different examples across a variety of product types, industries, and causes.

1. US Ski and Snowboard team’s fragmented data management

The US Ski and Snowboard Team manages dozens of Olympic athletes and supports over 450 sports clubs and 30,000 student-athletes across the country. Over time their legacy athlete data management system became fragmented. This resulted in a poor UX and significant operational headaches.

In addition to needing a modern solution to their legacy data management system, the US Ski and Snowboard Team wanted to create a better application experience for the young athletes and their families. And, they also wanted an ecommerce store that would integrate with their new internal solution.

The US Ski and Snowboard Team chose DevSquad to tackle the challenges of their legacy system and bring modern solutions that support more efficiency and growth. To meet their needs, we built a custom API that connected to their legacy system which immediately addressed many of their technical challenges. We also replaced their legacy desktop software with custom-built web software. Lastly, we performed a complete redesign of their main website, and ecommerce site.

What can we learn from this?

The first lesson learned from this example is to understand the challenges you are facing and your future objectives when addressing your legacy program. This allowed the ecommerce store to be directly integrated into the new single management and reporting system. The result being increased revenue and reduced workload.

The second lesson learned is that integrating legacy systems can be a combination of micro-solutions. Here the API integrated the data management system while the desktop software and website required rebuilds. Utilizing a resource like DevSquad can help you find the right balance of integration and rebuilding of your legacy system.

2. Walmart's legacy software and cloud infrastructures

Walmart is making several big changes. They are creating an abstraction layer to combine their preferred public cloud providers, their internal hybrid cloud, and their edge computing nodes. They've named the strategy the Triplet Model, and it will allow them to deploy workloads with the maximum flexibility, making failover super fast.

“Portability is more important than cost; it’s how we build resiliency. Each triplet is located milliseconds from each other so we can use compute in one place and data in another," explained Kevin Evans, Vice President of Infrastructure Services at Walmart, when speaking to Silicon Angle. It’s much easier to fail out of a provider in the same region to another provider. We started out looking to leverage around cost, but it’s transitioned into leverage around resiliency.”

The company has also been making changes to their legacy software, including migrating to software containers.

All in all, these updates have allowed the company to go from 1,000 monthly website backend updates to over 170,000 monthly updates.

What can we learn from this?

Walmart is truly on the cutting edge, and sometimes that means adopting more centralization rather than edge computing. Their team is prioritizing resiliency and flexibility, which will ultimately cut costs in the long run.

With the 1700% improvement in website updates, it's clear that the company is making an investment in e-commerce to keep pace with Amazon.

3. BlackBerry's software hurdles

Everyone knows that Blackberry failed not long after the iPhone came out. But many assume this is solely due to their outdated hardware—that clunky keyboard instead of a fully touchscreen interface.

However, there are two major legacy system elements at play in their downfall:

Text messages couldn't be sent to other device types (only other Blackberries).

They weren't quick enough to launch their own app store, so functionality was limited to internally-built features.

Functionality was overly focused on enterprise and business use cases, as opposed to consumers.

If it weren't for the legacy software issues, they could've owned a good chunk of the market, as many people still miss those keyboards. They could've at least offered the keyboard style for a while and used their software improvements to buy time to design a new, more modern device.

TicTok about Blackberry's legacy system

Interestingly, the company didn't totally die out. While they missed out on the potential to earn Apple's current net worth of over 2 trillion dollars, BlackBerry does have a net worth of over 2 billion dollars.

How? In an impressive pivot, the company is now a provider of cybersecurity solutions (for enterprises, of course).

What can we learn from this?

There are a couple of big lessons.

For one thing, businesses of any type can be destroyed by legacy systems, not just software providers.

For another, this is a good example of listening to your audience. BlackBerry mistakenly chose enterprise users as their audience, but they were at least able to pivot and deliver solutions to this audience that kept the business successful—although not nearly at the level of success that they could have been had they chosen to appeal to consumers.

4. Fanatic's CI/CD fires

Fanatics is an online retailer for sports apparel and replica jerseys. They offer hundreds of thousands of products with the logos and athlete names of professional and national sports teams.

Their outdated CI/CD infrastructure was causing tons of fires and patches that the cloud team constantly had to deal with. According to the GitLab case study, these issues "slowed down release times, stopped the deployment of block ends, and caused memory leaks."

Guilherme Gonclaves, the cloud tech lead, chose GitLab to help overhaul their legacy tooling because the CI/CD platform would be more stable and could integrate with their existing infrastructure.

With the updated tooling, the team has experienced several benefits, including spending more time on innovation and less time putting out fires, the ability to put more focus on continuous deployments, and improved collaboration with the engineering team. Builds are running well and not failing.

What can we learn from this?

Sometimes an application's code or programming language or backend architecture isn't the problem. The legacy DevOps and DevSecOps processed and tools that support development can be just as dangerous, so make sure to update these when issues arise.

5. Dovetail’s legacy PLM system

Dovetail Workwear is one of the largest exclusively womens workwear companies in the world. Founded in 2018 by three women who saw the need for functional and stylish workwear for women. They sell work shirts, tops, overalls, pants, and outerwear in retail stores and DTC from their website.

Designer Sara DeLuca describes the company's legacy PLM system as a combination of multiple spreadsheets and email exchanges. This introduced many discrepancies in the data and significant room for human error when updating the product information.

With a focus on size inclusivity, one of the biggest hurdles of the legacy PLM system was managing the large number of Stock Keeping Units (SKUs) for each style. 

In their first attempt to modernize and improve the system they chose a budget friendly PLM system to tackle their issues. The compound sizing that resulted from the size inclusivity was too much for the system to handle. Dovetail had to create several work-arounds in order to use it. Ultimately, the work-arounds needed to make the PLM system do what they needed was so time intensive that they were unable to create a merchandise sheet for the season.

Dovetail workware turned to Centric Software and their Centric PLMTM system. This gave them the needed flexibility to manage their extensive sizing. The upgraded PLM system completely revolutionized the business from a process standpoint by centralizing the entire process in one place.

What can we learn from this?

Understand your needs and do your research when choosing a software. The complexities of the Dovetail product lines were not met with the cheaper PLM solution. This ultimately ended up costing the company in the added workload to implement the work-arounds as well as not having a merchandise sheet for a whole season of clothing.

6. Insight Global's legacy backup solution

Insight Global is a large staffing agency, and they need to protect tons of sensitive staff data, from names and social security numbers to payroll data. They were relying on their own internally-built legacy backup solution. Ransomware attacks were escalating, and although the company hadn't experienced a major data breach yet, they knew that with their old solution it was only a matter of time.

To resolve these fears, the company completely replaced its internal solution with the Veeam Availability Suite™, which is poised to better protect against ransomware.

“Our business can’t run if data is unrecoverable, so we made some changes to our backup strategy," said Jordan Tazewell, Disaster Recovery Engineer for Insight Global, in a press release. "The first thing we did was ensure that the backup solutions we considered offered fundamental features: immutability to protect against ransomware."

The new solution proved effective at restoring backups during a system failure and during a major user error test.

What can we learn from this?

Sometimes, you might be able to replace legacy systems with on-premise or SaaS solutions, without having to re-build your own systems. In this case, you'll likely still need custom development work to integrate your chosen solutions together and with your existing tech stack.

7. The Navy's legacy helicopter systems

A helicopter is the most dangerous to drive during low visibility conditions caused by fog, wind, dust, sand, snow powder, and sea mist (when landing helicopters on ships at sea).

“Rotary-wing pilots flying newer rotorcraft like CH-53K have the benefit of augmented landing tech built in,” said Naval Air Warfare Center Aircraft Division (NAWCAD) engineer Matthew Rhinehart in a Navy news story. “But there are thousands of legacy helos across the DOD that don’t—it’s a safety challenge for which we’ve engineered a proven-successful solution.”

The Navy engineering team has created two prototype systems that will be integrated into the legacy systems of older aircraft to minimize drift and help pilots land safely.

What can we learn from this?

At the most extreme end of the downsides, legacy systems have the power to affect health and safety. But solutions can be created to salvage costly equipment and vehicles, while still providing modern safety features.

Maybe lives aren't at risk when it comes to your legacy system. But you can still take something away from this example. You might be able to update the most critical part of your system, without refactoring or rebuilding the entire thing.

8. The entire mortgage industry's outdated tech

The mortgage industry as a whole is ripe for disruption. It is one of the slowest, most archaic industries.

“What has happened now is some of these software technologies, especially in industries like the mortgage industry, or you can see maybe the travel industry, are running on legacy systems that were built in the 70s or the 80s, which is essentially kind of a Jurassic period. I mean, if you think of the progression of technology, that’s a really long time, 40 years," said Souren Sarkar, CEO of Nexval in an interview.

Souren's company along with Floify, Haptik, and Finicity are all working on solutions to the many problems that the mortgage industry presents.

What can we learn from this?

There's a lot of opportunity here. Entrepreneurs can create software and services to help lenders modernize their systems. Meanwhile, if you work for a mortgage lender, you could research new SaaS solutions that might address your problems, or rebuild your internal legacy systems with a trusted product management team.

9. The FBI's warning about legacy medical devices

The FBI released a report stating that medical devices running on legacy software can pose major risks to:

  • Patient safety

  • Healthcare organizations' data security and integrity

  • Healthcare organizations' operations

Devices can send inaccurate data to medical professionals or fail to transmit data. Worse, they can serve as entry points for cybersecurity attacks.

The report says: “Medical device hardware often remains active for 10-30 years, however, underlying software life cycles are specified by the manufacturer, ranging from a couple months to maximum life expectancy per device allowing cyber threat actors time to discover and exploit vulnerabilities."

Medical organizations are encouraged to use endpoint protection, encrypt data, and require passwords for all medical devices.

However, much of the responsibility should instead fall on the creators of these devices.

What can we learn from this?

If you're an entrepreneur, these kinds of reports are like having built-in product validation. Researching known problems can help you discover and vet ideas for SaaS and other types of tech businesses. What other types of systems are in need of modernization? How can you build a business that would address these?

DevSquad offers software modernization services and we can assist medical device providers in creating more secure, integral, and effective software.

How to modernize legacy software

Software modernization refers to the massive undertaking of refactoring and rebuilding legacy systems.

The project should follow these steps:

  1. Architecture audit

  2. Code audit

  3. UX audit

  4. Product strategy

  5. UX design

  6. Refactoring

  7. Performance testing

  8. Quality assurance

  9. Roadmap planning

Frequently asked questions about legacy systems

Why should legacy systems be modernized?

There are several reasons why legacy systems should be modernized. On the business side, operational efficiency is on the top of the list. Other reasons include access to modern functionality, better utilization of existing data, and faster implementation of new solutions and technologies. 

The high costs of legacy system support and maintenance can also make the modernization of your system worth it. And, modernizing legacy systems typically generate better user experiences—which is a plus for increasing sales and reducing churn.

What are the best practices to follow when updating a legacy system?

The best practices for updating a legacy system can be divided into five steps: (1) Clarify purpose and requirements; (2) Asses the legacy system’s capabilities; (3) Research potential resources and solution providers; (4) Choose the type of upgrade to implement and implement it; and (5) Test the updated system and plan for long-term maintenance.

Make sure to complete each step before moving forward and don’t rush the process. Updating a legacy system takes time and a lot of effort. If done right though, you’ll reap the benefits for years to come. And, don’t forget to document everything.

What are the risks of not updating a legacy system?

From a business operations standpoint, not modernizing your legacy system introduces a lack of compatibility that hinders business agility and innovation. It also limits the ability to scale and adapt to evolving market demands. The extensive manual effort typically required to maintain legacy systems also introduces significant opportunity for human errors. Overall, not updating a legacy system generates the risk of losing your competitive advantage as your competitors leverage more advanced technologies.

Legacy software and hardware introduces security risks as well. This can expose your data to breaches and cyberattacks. And, legacy systems may not be able to meet current regulatory standards which can lead to legal ramifications and fines.


We're experts in software modernization for enterprises and government agencies. Learn more about DevSquad and contact us for a free strategy session.

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