Legacy Application Modernization: Strategies, Benefits and Solutions

Legacy application modernization refers to the process of transforming an organization's existing systems into a cloud-first model, often encompassing broader legacy system modernization efforts. This typically involves migrating on-premises applications to public, private or hybrid cloud environments, followed by rebuilding and enhancing them using cloud-native tools, advanced technology stacks and modern services.

In this blog, we'll begin by examining the key benefits of application modernization, identify the most common targets for transformation, outline actionable steps to take, address potential challenges during the process and explore the most effective approaches to modernization.

Lastly, we'll showcase an EPAM-developed modernization platform as an example of innovative solutions designed to drive successful legacy application modernization efforts.

Benefits of Application Modernization

Legacy app modernization offers numerous advantages that can significantly impact an organization's efficiency, security and overall performance. By updating existing systems and adopting modern technologies, businesses can discover new opportunities and develop a competitive advantage.

Below are the key benefits of legacy application modernization:

• Increased Agility and Speed to Market: Modernized applications enable faster response to market changes and customer needs.

• Improved Customer Experience: Enhanced functionality, usability and reliability in modernized applications deliver superior customer experiences.

• Boosted Productivity: Automation and integration of advanced tools within modernized applications drive employee efficiency and streamline workflows.

• Enhanced Security: Legacy systems are prone to vulnerabilities, while modernized solutions incorporate advanced security features that protect sensitive data.

• Reduction in Technical Debt: Outdated systems often come with inefficient architectures and legacy practices, making updates slow, costly and risky. Application modernization reduces this technical debt.

• Better Data Management: Modernized applications offer superior data management capabilities, enabling organizations to optimize decision-making and gain deeper insights into their operations.

• Cost Savings: Legacy systems incur high maintenance costs due to outdated infrastructure. Modernization reduces these expenses through operational efficiency.

• Improved Scalability: Legacy systems frequently struggle with increasing traffic, data growth and expanding functionalities. Modernized solutions provide the scalability needed to adapt to business demands with minimal disruption.

• Enhanced System Performance: Modernized applications leverage cutting-edge technologies to improve system performance and meet current and future requirements.

Application modernization is not a one-time fix; it is a strategic, long-term process aimed at continuous improvement. Careful planning and execution are critical to ensuring the success of your modernization efforts and achieving sustainable growth.

Legacy Application Modernization Targets

Modernizing existing systems often provides a more time-saving and cost-effective approach compared to the complete redesign and rebuilding of business logic and processes. By identifying and transforming outdated applications, organizations can improve performance, scalability and compatibility with modern technologies.

Below are the most common types of applications targeted during the legacy modernization process:

• Applications Built with Outdated Programming Languages or Technologies: Systems developed in languages such as Fortran, COBOL or Pascal, as well as legacy frameworks, often lack the flexibility and support required for modern business needs.

• Linux Web Applications and Servers on Obsolete Hardware: Applications and servers running on old or unsupported hardware are prone to inefficiencies and increased risks, making them a priority for modernization efforts.

• Legacy SAP Applications: Organizations often target SAP systems for modernization to align with evolving business requirements and leverage cloud-native capabilities.

• On-Premises SQL Databases: Migrating outdated SQL databases to cloud environments ensures improved scalability, reliability and integration with advanced analytics tools.

• Custom-Built Enterprise Resource Planning (ERP) Systems: ERP systems designed with legacy architectures require modernization to enhance functionality, streamline operations and support long-term growth.

• Outdated Customer Relationship Management (CRM) Systems: Transitioning legacy CRM systems to modern platforms improves data management, customer engagement and overall business outcomes.

Modernizing Legacy Applications with Risk Considerations

While it offers many benefits, not all applications are well-suited for modernization. Some may not justify the time, resources or security risks involved. These can be the legacy solutions of the following types:

• Mission-Critical Systems: Transforming legacy systems that are integral to core operations and critical business processes (e.g., banking software) may be too complex without risking significant disruption to critical functions.

• Highly Specialized Applications: Custom applications for niche industries or those tightly coupled with specific hardware may not benefit from modernization and the introduction of new technologies due to limited impact and specialized needs. Such applications usually need low-level access to hardware and operating systems.

• Real-Time Systems: Applications requiring low latency, such as those in manufacturing or finance, may struggle to perform in cloud environments and should be left as is.

• Legacy-Dependent Software: Applications relying on outdated software, hardware or specific operating systems may face compatibility challenges with modern technologies and new platforms, making them poor candidates for modernization.

• Short-Lived or Low-Impact Applications: Temporary or low-impact applications may not warrant the investment required for a full modernization effort and can be replaced or retired.

• Regulated Applications: Applications in industries with strict compliance requirements may encounter additional obstacles when modernizing due to security and data handling constraints.

In these cases, maintaining, replacing or retiring the application may be more cost-effective than attempting modernization.

Main Modernization Approaches

Many organizations begin their modernization journey with a lift-and-shift migration — transferring applications from on-premises data centers to the cloud to quickly access the core benefits of the cloud, such as scalability, cost optimization and operational flexibility.

Following this, companies can adopt more sophisticated strategies, such as replatforming, re-architecting or rebuilding to incorporate updated features and align with industry best practices, thereby creating systems that are both future-ready and aligned with business goals.

Based on your organization's specific needs, you can choose the most appropriate modernization strategy:

• Lift-and-Shift (Rehost): This approach involves moving applications from their old environment to the new one with minimal changes to the existing code. It is ideal for organizations seeking a fast transition to the cloud while maintaining infrastructure cost efficiency.

• Refactor (Repackage): Refactoring focuses on making small code changes to enable applications to connect seamlessly with cloud services. This strategy offers improved productivity and ensures applications can fully leverage cloud environments while maintaining swift execution.

• Replatform: Replatforming falls between rehosting and refactoring. It requires making targeted code changes to optimize applications for cloud technologies, enhancing functionality and efficiency while reducing operational complexity.

• Re-architect: For organizations needing greater scalability and flexibility, re-architecting is a suitable choice. This approach involves modifying application architecture and extending functionality to meet the demands and capabilities of cloud-native environments.

• Rebuild (Rewrite): Rebuilding is used for applications with limited functionality, lifespan or adaptability to modern environments. While this approach requires significant effort, it creates cloud-native solutions that meet long-term organizational goals and ensure technological relevance.

• Replace: In cases where existing applications cannot meet current or future business needs, replacing them with off-the-shelf solutions becomes the best option. This approach can save development time and resources. However, it may introduce challenges such as disruptions to existing processes and limited customization for future modernization efforts.

Application Modernization Activities

Modernizing Applications: Techniques and Technologies

Modernizing applications involves adopting advanced techniques and technologies to improve scalability, efficiency and resilience. These efforts should seamlessly integrate with other systems to avoid silos and promote operational harmony. Below are six essential strategies for enabling successful application modernization:

1. Move to Containerized Environments: Package applications and their dependencies into lightweight, portable containers to ensure consistency across different environments, from development to production. This approach accelerates deployment, simplifies dependency management and supports microservices architectures, enabling greater scalability and flexibility.

2. Implement CI/CD Practices: Leverage continuous integration and continuous deployment (CI/CD) techniques to automate the software delivery pipeline. Regular integration of changes and automated deployments enable faster, more reliable releases while reducing time to market. Popular CI/CD tools include Jenkins, GitLab CI and Azure DevOps.

3. Enhance Monitoring and Logging: Adopt observability tools like Grafana or the ELK stack to monitor application performance and troubleshoot effectively. Pair these with frameworks like OpenTelemetry to collect and analyze traces, metrics and logs, empowering teams to maintain a reliable and high-performing architecture.

4. Establish Robust Backup Protocols: Automate backup strategies to safeguard data integrity and ensure recovery in the event of failures. Clearly define recovery time objectives (RTO) and recovery point objectives (RPO) that align with your organization's business continuity plans to build a resilient system.

5. Adopt GitOps for Automation and Traceability: Use GitOps principles to manage infrastructure and application deployments via Git repositories as the single source of truth. This approach improves traceability, facilitates automation and enables teams to detect and address configuration drift more effectively.

6. Migrate to Cloud-Native Environments: Re-architect applications to leverage cloud-native services, such as managed databases, container orchestration platforms or serverless computing. This modernization approach enhances flexibility, reduces operational burdens and enables better alignment with cloud-driven business initiatives.

While these steps represent widely adopted modernization practices, not all may be necessary for every application. Teams should assess their specific needs and prioritize approaches that deliver the most impact.

The Modernization Challenge

Implementing one modernization step may not be overly complex, but following all the necessary steps to fully modernize a legacy application presents significant challenges. Such a transformation can span years and requires dedicated DevOps expertise.

Using Tools to Simplify Modernization

Rather than starting from scratch, businesses can leverage specialized, ready-to-use application modernization platforms to accelerate their efforts. These solutions are designed to embed modern techniques swiftly and reduce the overall time and complexity of the modernization process.

For instance, EPAM offers KubeRocketCI (KRCI), a comprehensive application delivery platform based on years of industry expertise. KRCI streamlines legacy application modernization by providing organizations with the tools and best practices to transition their systems into modern, containerized architectures. Its cloud-agnostic design ensures flexibility and broader infrastructure compatibility, helping businesses modernize faster and more effectively.

KubeRocketCI: Simplifying Cloud Application Modernization

KubeRocketCI is an open-source SaaS/PaaS platform designed for cloud application modernization. Licensed under Apache License 2.0, it offers a predefined set of CI/CD patterns and tools that enable users to initiate product modernization quickly and efficiently. With built-in capabilities like versioning, branching, building and deploying, KubeRocketCI streamlines key development and deployment processes.

The platform includes essential features such as:

• Static Code Analysis: Ensuring code quality through automated scans.

• Security Checks: Identifying potential vulnerabilities before deployment.

• Linters and Validators: Enforcing coding standards and improving code reliability.

• Dynamic Feature Environment Provisioning: Facilitating agile testing and faster feature rollouts.

KubeRocketCI consolidates industry-leading open-source CI/CD tools and leverages the power of Kubernetes/OpenShift, enabling seamless management of CI/CD pipelines. It is flexible enough to address legacy application modernization in diverse environments, including isolated workloads (on-premises), cloud and hybrid infrastructures.

Whether organizations are taking their first steps in legacy application modernization or scaling their operations, KubeRocketCI offers a reliable and efficient pathway to modern, containerized architectures.

Choosing the Right Technical Stack for Application Modernization

To ensure a successful modernization strategy, choosing the right tools is crucial. Several key criteria can narrow the horizon of potential solutions and ensure alignment with organizational needs:

1. Functional Requirements: The tool must address customer expectations, business objectives and align with the organization's technology stack.

2. Non-Functional Requirements: These aspects determine how effectively a tool can be sustained over time. Performance, cost efficiency, maintainability and availability are equally important.

3. Recognition: Tools should be reliable and publicly acclaimed. Membership in organizations like the Cloud Native Computing Foundation (CNCF) is a valuable indicator of a tool's credibility and adherence to cloud-native best practices.

4. Community and Ecosystem: A strong, active community greatly enhances a tool's value through frequent updates, robust security, extensive documentation and troubleshooting support.

Application Modernization Challenges

Modernizing applications can deliver transformative benefits, but it comes with several critical challenges that developers must address. These challenges often shape the approach and strategy for modernization efforts:

1. Managing and Configuring Infrastructure: This includes considerations such as governmental regulations, cost constraints, scalability needs and availability preferences.

2. Containerizing the Environment: It involves transforming your application into standalone containers that are portable, consistent and scalable while enabling greater flexibility for deployment across environments.

3. Creating CI/CD Pipelines: CI/CD pipelines accelerate development cycles, maintain reliability and automate workflows to reduce time to market.

4. Designing Quality Gates: Incorporating automated testing and validation mechanisms to establish quality gates that prevent substandard code from reaching production.

5. Configuring Third-Party Integrations: Modern applications often rely on external services like databases, APIs and monitoring tools to ensure compatibility, maintain functionality and uphold security across interconnected systems.

6. Adjusting Development Practices for Various Frameworks and Tools: Supporting polyglot microservices and diverse frameworks adds complexity. Developers must embrace modern practices for flexibility across technological stacks.