Best Ways to Modernise Legacy Systems

Wrestling with keeping your IT infrastructure up to speed is more common as technology advances with each passing day. Many organisations find themselves tethered to outdated systems that, while reliable, are rapidly falling behind the times. The key to revitalising these digital dinosaurs? Take a strategic approach to modernise legacy systems with Capaciteam’s IT specialists. Keep reading to learn how to transform your IT framework from outdated to outstanding.

What are Legacy Systems?

Legacy systems are outdated computer systems, programming languages, software, and applications that are still in use but no longer being actively developed or supported. Many companies rely on legacy systems built decades ago to run critical business functions.

Should you modernise your legacy system?

There are a few reasons why modernising legacy systems makes sense:

  1. Security risks. Older systems are more vulnerable to cyber threats and hacking because they lack modern cyber security management.
  2. Saving costs. Maintaining outdated systems requires specialised resources and parts which can be expensive. Migrating to modern platforms reduces costs.
  3. Scalability and agility. Modern systems are built to scale and integrate new features easily. This allows companies to respond faster to changes. Legacy systems are rigid and difficult to update.
  4. Lack of technical support. Technical support and spare parts can be difficult to find with outdated systems. This poses risks to business continuity.
  5. Workforce challenges. Younger tech employees prefer to work with modern languages and systems. Legacy systems make it harder to attract and retain top talent.

While the risks of legacy systems are clear, modernising them is also challenging. CIOs must build a business case, plan migrations carefully, provide training, and ensure no disruptions to critical operations. However, with the right strategy and execution, legacy modernisation can transform a business.

 A team of IT professionals collaborating around a large digital screen, trying to modernise legacy systems.
The times are changing – so should your tech stack.

Top Benefits of Modernising Legacy Systems

  • Reduced risks. Old systems are prone to crashes and security issues, putting data and operations at risk. Modernisation eliminates vulnerabilities and single points of failure, reducing downtime and ensuring business continuity.
  • Lower costs. Maintaining outdated technology is expensive. Migration to modern platforms reduces licensing fees and overhead and minimises costly repairs and troubleshooting.
  • Improved agility. Modern systems are flexible, scalable, and adaptable to change. This allows companies to pivot faster to capture new opportunities and meet shifting customer needs.
  • Enhanced productivity. Updated tools are integrated, automated, and user-friendly, streamlining processes and workflows. Employees can do more in less time with less hassle, boosting innovation, collaboration, and output.
  • Future-ready technology. Modern platforms incorporate emerging tech like AI, AR/VR, blockchain, and cloud computing. This future-proofs businesses and ensures they have the capabilities to compete going forward.

How to Evaluate Your Legacy System

Before modernising legacy systems, you need to evaluate your existing systems. This evaluation should encompass:

  • Workload: Analysing the business value and criticality of applications.
  • Architecture: Reviewing infrastructure for potential improvements.
  • Financial considerations: Identifying budget constraints and optimisation opportunities.
  • Risk: Considering potential disruptions and their impacts.
  • Operations: Assessing necessary skill sets and training.
  • Security: Planning for data protection and compliance​​.

3 Best Options To Modernise Legacy Systems

Modernisation typically requires custom development to integrate new front-ends, APIs, and cloud services with legacy back-ends. It may also require some data migration and business process changes.

The best approach for your organisation depends on your goals, resources, risk tolerance, and legacy systems. In many cases, multiple strategies are needed to modernise legacy environments. The key is to begin with a comprehensive roadmap to guide your modernisation journey:

#1: Replatforming to the Cloud

Migrating legacy systems to the cloud, also known as “replatforming”, is one of the most effective modernisation strategies. The cloud offers scalability, flexibility, and cost efficiency that on-premises infrastructure lacks.

A futuristic illustration of the cloud.
The cloud should be your go-to when you start modernising your legacy systems.

Replatforming involves shifting hardware, storage, and other resources from a private data centre to a public cloud provider like Amazon Web Services (AWS), Microsoft Azure, or Google Cloud Platform (GCP). You get all the benefits of the cloud without rebuilding applications from scratch.

Advantages of replatforming:

  • Cost savings. The cloud’s pay-as-you-go model means you only pay for the resources you use. No more wasted capacity or upfront capital costs.
  • Scalability. Easily scale resources up or down as needed. The cloud is designed for elasticity.
  • Agility. Quickly deploy or decommission resources through a web console or API. Spin up temporary resources for testing and development.
  • Reliability. Major cloud providers have high availability, redundancy, and disaster recovery built-in.
  • Security. Cloud providers invest heavily in security and compliance. They have sophisticated tools for managing users, roles, credentials, encryption, etc.

How to replatform?

To replatform, you’ll need to:

  1. Choose a cloud provider and sign up for an account. Evaluate each provider based on your needs and priorities.
  2. Migrate your data to the cloud. This includes databases, file shares, object storage, etc. Use native cloud services for storage.
  3. Deploy your applications in the cloud. You can lift and shift VMs, use the platform as a service, or rearchitect applications to be cloud-native.
  4. Connect resources. Update DNS, firewall rules, and networking to direct traffic to your applications in the cloud.
  5. Decommission on-prem infrastructure. Once fully migrated, you can shut down your private data centre to maximise cost savings.

Replatforming legacy systems to the cloud is a proven, low-risk approach to modernisation that provides immediate benefits. While not as transformative as rearchitecting from scratch, replatforming is an excellent first step in any cloud journey.

#2: Rehosting legacy systems

Rehosting, known as “lift and shift“, involves moving your legacy system to a modern infrastructure without redesigning the application. This is a popular option as it requires little to no code changes, allowing you to move off outdated infrastructure swiftly.

To rehost, you transfer your legacy system to a contemporary hardware and software environment like the cloud. The difference with replatforming is that rehosting does not involve modification to take advantage of the new cloud infrastructure. Here, you configure the system to work as before.

Although rehosting doesn’t change your actual application, it provides modern infrastructure advantages such as:

  • Scalability. Easily scale computing resources up or down as needed.
  • Cost efficiency. Only pay for the resources you use.
  • Reliability. Built-in redundancy and disaster recovery.
  • Flexibility. Quickly adjust resources to meet changing demands.
  • Productivity. Free up your IT team to work on more strategic tasks.

Is rehosting a good option?

While rehosting does provide infrastructure benefits, your application remains unchanged. Any existing issues or inefficiencies in the system design or code will remain. For this reason, rehosting is often a first step before pursuing redevelopment or replatforming strategies. It allows you to get off outdated infrastructure quickly while buying time to implement intense modernisation approaches.

Rehosting could be a good option if you aim to get off legacy infrastructure with minimal effort. However, to truly optimise your system and technical debt reduction, you’ll likely need to pursue redevelopment or replatforming in addition to or instead of rehosting. The right approach depends on your priorities, timeline, budget, and how long you want your modernised system to meet your needs.

3. Refactoring/re-architecting monoliths

Legacy systems often started as single, large applications known as monoliths. As these systems age, they become more difficult and risky to change. Refactoring and re-architecting monoliths into more modular applications is one of the best ways to modernise them.

Refactoring refers to restructuring existing code without changing its external behaviour. This could include:

  • Breaking up large methods into smaller, more focused ones.
  • Removing duplicated logic.
  • Renaming unclear variable and method names.
  • Reorganising methods and classes to make the code easier to understand.

How to re-architect monoliths?

Re-architecting goes a step further by making major changes to the system design and code structure. Some options for re-architecting monoliths include:

  • Extracting business logic into separate services: For example, you could have one service for placing orders, another for billing, and another for shipping. These services can then be scaled and evolved independently.
  • Adopting a modular architecture: Break the monolith into separate modules, each focused on a single business capability. The modules can then communicate through APIs. This makes the overall system more flexible and maintainable.
  • Migrating to microservices: Decompose the monolith into small, independent services. Each service is focused on a single business capability and can be deployed, scaled, and upgraded independently. Microservices require significant changes but can provide substantial benefits.
  • Implementing an API layer: Expose parts of the monolith’s functionality through APIs that can be consumed by web and mobile apps. This at least separates the monolith from the front-end clients and opens opportunities for future decomposition.

Refactoring and re-architecting monoliths unlock their business value and allow them to live on as a vital part of your IT infrastructure. While it requires time and resources, modernising monoliths in this way enables innovation and reduces long-term risks. The result is a system that is open, modular, and built for change.

Rearchitecting with microservices

Microservices are an architectural style where apps are built as a collection of small, independent services. Each service is self-contained and implements a single business capability.

For legacy monolithic systems, breaking them up into microservices offers several benefits:

  • Scalability: Microservices can scale independently, so you only have to scale the services that need more resources. This is more cost-effective than scaling an entire monolithic app.
  • Agility: Microservice teams can release updates to their service frequently without impacting other services. This speeds up innovation.
  • Fault isolation: Issues in one microservice won’t impact others so problems can be isolated and fixed more easily.
  • Tech flexibility: Different microservices can use different tech stacks based on their needs. Teams have more flexibility to choose tools that suit the job.

To rearchitect a monolithic system with microservices:

  1. Identify business capabilities to extract into separate services. Look for areas that may benefit from scaling or updating independently.
  2. Plan how the services will communicate. APIs are commonly used for microservice communication so you should design APIs to share data between services.
  3. Extract the code for a single capability into a separate codebase for its microservice. Repeat this step iteratively for other capabilities.
  4. Set up mechanisms for service discovery, load balancing, and fault tolerance to manage the suite of microservices.
  5. Monitor your microservices closely as you launch them. Fix any issues that arise from inter-service communication or dependency failures.
  6. Continue improving and optimising your microservices over time. Shift more capabilities into microservices as needed.

Migrating to microservices is challenging, but it can revitalise and modernise legacy systems and make them fit for the current digital world. With an iterative approach, you can transform your monolith into a suite of microservices to build a flexible, scalable architecture.

When to Rewrite Legacy Systems

Legacy systems that have been in place for years often reach a point where rewriting them from scratch makes more sense than continued patching and updating. How do you know when it’s time for a rewrite?

A contemporary office environment showcasing a modern IT setup with current technology
Sometimes, your system needs a full revamp.

Frequent downtime and outages

If your legacy system experiences frequent outages or crashes or needs constant maintenance to keep it running, it may be more cost-effective to replace. The money and resources spent on constant upkeep could be better invested in a new system built on modern architecture.

Difficulty adding new features

If your business needs are evolving but your legacy system is difficult to enhance with new features, a rewrite will allow you to build a flexible system that can grow with your company. Trying to bolt on new functionality to an ageing system often creates a technical debt that slows progress.

Security risks

Older systems were not designed with modern security practices in mind. If your legacy system poses vulnerabilities to cyber threats or difficulties complying with HIPAA or GDPR, a rewrite is necessary to safeguard your company and customer data.

Vendor support ending

Many legacy systems rely on underlying software, hardware, and tools unsupported by vendors. If support for components of your system is ending, you risk running an unstable system with no help available to fix issues. The only option here is to migrate to a new system under active support.

Cost-benefit analysis

Ultimately, you weigh the costs and risks of keeping your old system against the investment required to modernise your legacy system. Factor in costs like maintenance, opportunity, inability to grow efficiently, and potential impacts of downtime or security events. If a new system will save money and enable progress in the long run, it’s worth the upfront effort and expense of rewriting from scratch.

A modern replacement built on current technology will ensure your company’s systems can support its needs today and for upcoming years. While rewriting legacy systems is complex, it helps avoid the traps of the past and provides a solid foundation for the future.

FAQs on Modernising Legacy Systems

What exactly is a legacy system?

A legacy system is an outdated computer system, programming language, or application still critical to day-to-day business operations. These systems are typically older technology that companies still rely on to run their business. They often run on outdated hardware and software, making maintenance difficult and expensive.

Why should I modernise legacy systems?

Improved security – Older systems are more vulnerable to cyberattacks and data breaches. Updating to modern technology helps patch security holes and better protect sensitive data.
Increased efficiency – Newer systems are often faster, more reliable, and integrate better with current technology stacks. This can streamline business processes and workflows.
Reduced costs – Maintaining outdated hardware and software is expensive. Migrating to modern systems reduces spending on patches, upgrades, and maintenance.
Improved scalability – Modern systems are built to handle increased data, transactions, and users. This makes it easier to scale as your business grows.
Access to new features – Contemporary software offers advanced features like predictive analytics, AI, and automation that aren’t available in legacy systems.
Better UX – Modern interfaces and architecture provide an improved user experience. This makes systems easier to use and interact with.

What are the main approaches to modernising legacy systems?

Rebuild – Scrap the legacy system and build a new modern system. This is high risk but often necessary for outdated systems.
Revamp – Make major changes and upgrades to a legacy system to modernise its infrastructure, software, and architecture. This “renovates” the system without completely rebuilding it.
Retain – Keep the legacy system as-is but build a separate modern system and slowly transition over. The legacy system acts as a backup until the migration is complete.
Retire – Decommission the legacy system and replace it with an off-the-shelf or custom-built modern solution. Only feasible if the system is redundant or non-critical.

Final Thoughts

Despite the clear benefits, it is challenging to modernise legacy systems, with obstacles such as resistance to business process changes, balancing the risks involved, and managing data effectively. A successful modernisation project requires careful planning, stakeholder alignment, and a strategic approach to overcome these obstacles​. When you find a trusted IT staffing partner, you can leave it to them to do all the heavy lifting and reap the benefits of your upgraded, modern system.