A Practical Guide to Cloud Legacy System Migration

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Legacy application migration has become a buzzword that often finds its way into IT discussions. But what does it really mean, and why should you care?

Legacy application migration is the process of upgrading or using legacy programs and transitioning aging or outdated software systems to modern platforms. Why does it matter to migrate legacy anything? Because legacy applications, while once the crown jewels of tech innovation, can become ticking time bombs. They pose security risks, hinder agility, and are often costlier to maintain than to replace.

The pot of gold at the end of the migration rainbow includes more cloud computing resources, enhanced performance, improved security, cost savings and the ability to embrace new technologies, business processes, and methodologies. It’s like trading in your old flip phone for a shiny new smartphone – a game-changer.

What Is a Legacy Application?

A legacy application is an existing application that supports critical business operations but runs on an older stack. It may rely on outdated software, outdated technology, or a current legacy system that is hard to change safely. Many businesses keep legacy applications because they power essential business processes and store valuable data.

Over time, legacy systems struggle with poor performance, limited scalability, and rising maintenance costs. Vendor support can fade, security patches may arrive late, and security risks increase. Legacy apps also tend to depend on tight coupling, custom integrations, and older data formats, which makes system migration and cloud migration harder.

Legacy application migration typically involves both code migration and data migration processes. You’re not only moving apps to the cloud. You also need to migrate legacy data, validate existing data, and confirm that all the data still adheres to business rules in the new environment.

Modernization vs. Migration: When You Should Not Fully Migrate

Modernization focuses on enhancing an existing legacy system. Migration involves relocating workloads and data to a new platform and cloud environment. Many migration projects combine both approaches to protect business continuity and reduce operational costs.

Assessing the Need for Migration

Old software applications, known as legacy applications, sometimes reach a point where they’re no longer up to the task. In this part of our guide on legacy application migration, we’re going to explore the signs that tell you it’s time for an upgrade. These signs are like warning lights, indicating that your old software needs a refresh.

Identifying signs

From the software company no longer providing support to your application crashing too often, these signals are like clues that it’s time to migrate legacy applications:

• Dwindling vendor support
• Declining performance
• Frequent crashes
• User complaints

One of the earliest signs that may trigger the need for migration is dwindling vendor support or outdated software systems. When the software or platform your application relies on is no longer receiving updates, patches, or security fixes, it becomes increasingly vulnerable.

Performance degradation is like the warning lights on your dashboard flickering. Sluggish response times, longer loading periods, or increased resource utilization are indicators that your legacy application may be struggling to keep up with modern demands.

Just as a car breaking down frequently signals mechanical issues, frequent application crashes are a glaring sign of underlying problems. These crashes disrupt productivity, frustrate users, and can even result in data loss or corruption.

Users are often the first to experience issues, and their feedback can be invaluable in identifying pain points within the application.

Evaluating the current state

• Health checkup: This involves a thorough examination of the application’s health, architecture, and performance metrics
• Identifying vulnerabilities: What is causing those hiccups in the performance and reliability of the legacy software? Is it outdated hardware, inefficient code, or security gaps? Understanding the root causes is crucial for informed decision-making

Business impact

• Downtime: Extended outages due to legacy software failures can paralyze operations, disrupt customer service, and result in significant financial losses
• Data breaches: Failure to successfully migrate can leave security vulnerabilities unaddressed, potentially leading to data breaches, leaks, or cyberattacks
• Stuck in IT quicksand: An IT system that no longer meets business requirements is like quicksand slowly sinking your organization
• Financial losses and reputation damage: The financial repercussions of not migrating can be severe, encompassing lost productivity, increased maintenance costs, and missed business opportunities Additionally, the reputation damage resulting from service interruptions or data breaches can have lasting consequences

In summary, recognizing the signs that herald the need for migration, conducting evaluation of the existing system, and assessing the potential business impact are foundational steps in the decision-making process. Organizations must proactively address the health and well-being of their IT systems to ensure resilience, security, and continued competitiveness in the digital landscape.

Planning the Legacy Systems Migration

In IT, it involves defining goals, assessing scope, and creating a detailed plan with a well-defined timeline.

Let’s delve into these crucial aspects with a professional IT perspective:

Defining goals

Objective clarity: When initiating a migration, it’s paramount to define your business application goals with absolute clarity. Ask yourself, “What are we trying to achieve with this migration?” Is it enhanced system performance, increased scalability, cost reduction, continuous integration, or perhaps modernization to meet evolving business needs? By articulating these objectives precisely, you establish a clear direction for the system migration project.

Assessing scope

The Road ahead: Similar to planning a road trip, understanding the scope of your sstem migration efforts is crucial. It involves comprehending the full landscape of the migration effort. Scope assessment includes:
Complexity: Evaluate the intricacy of network architecture in your existing IT environment. Are there numerous dependencies, legacy systems, or third-party integrations? Recognizing complexity is vital to anticipate challenges.

Scale: Determine the scale of migration. Is it a single application, a suite of systems, migrating legacy systems and applications, or an entire data center? Understanding the breadth of migration helps allocate resources effectively.

Dependencies: Identify dependencies between applications and data, as well as any interdependencies within the migration project. Mapping these dependencies is akin to plotting waypoints on your journey to avoid unforeseen “potholes.”

Detailed plan and timeline

Precise navigation: A migration plan is your roadmap for the journey. It’s more than just a list of tasks; it’s a strategic document that guides every phase of migration. Elements of a well-structured and complete migration plan include:

Timelines: Define specific timelines for each new system and migration phase. Establishing deadlines for milestones keeps the project on track and ensures alignment with business objectives.

Milestones: Milestones are like signposts along the way. They mark significant achievements and progress during the migration of legacy software. Achieving milestones provides a sense of accomplishment and helps track project success.

Contingency strategy: Like having a backup navigation system, a contingency strategy is essential. It outlines actions to take if unexpected challenges arise. Contingencies could involve rollbacks, alternative routes, or resource reallocation.

Resource allocation: Allocate resources, including personnel, equipment, and budget, in a well-considered manner. This ensures that the project has the necessary support throughout its lifecycle.

Risk assessment: Consider potential risks and challenges at each phase of the migration. Develop mitigation strategies and incorporate them into the plan of moving your applications to the cloud.
In conclusion, the planning phase of migration is the foundational pillar upon which the entire project stands. Preparation minimizes uncertainties, reduces risks, and sets the stage for a successful migration journey in the dynamic landscape of IT.

Choosing the Right Migration Strategy

Migration strategies are like different routes on a map: rehost, replatform, or refactor. Each has its pros and cons, and the choice depends on your business requirements.

Rehosting (lift and shift)

Description: Rehosting entails relocating the existing application to a new environment with minimal alterations. This process typically involves transferring the application and its data to a different hosting infrastructure, often within a cloud computing environment. The primary objective is to reduce costs while maintaining the core functionality.

Pros: Rehosting is an economically efficient and relatively swift option that minimizes disruption to ongoing operations.

Cons: While cost-effective, this strategy may not bring significant improvements in terms of functionality, scalability, or performance. It might not address the underlying issues present in the legacy code.

Replatforming (lift, tweak, and shift)

Description: Replatforming represents a step beyond rehosting by making selective adjustments to the application to ensure compatibility with the new environment. These adjustments could involve updating elements like the operating system, middleware, or database while preserving the core code.

Pros: Replatforming enhances compatibility and offers the potential for improved performance and scalability. It typically carries a reduced risk compared to a full-scale rewrite.

Cons: This strategy may not fully capitalize on modern technologies, and certain legacy issues may persist.

Refactoring (rewrite or rebuild)

Description: Refactoring is a more comprehensive approach involving the rewriting or rebuilding of specific sections of the legacy application’s code using contemporary development practices and technologies. This strategy seeks to enhance code quality, maintainability, and scalability while preserving the application’s core functionality.

Pros: Refactoring yields improved performance, scalability, and maintainability. It also presents an opportunity to introduce new features and align the application with current business needs.

Cons: While offering substantial benefits, refactoring tends to be more resource-intensive and time-consuming compared to rehosting or replatforming. The increased complexity may lead to longer project timelines.

Rearchitecting (redesign)

Description: Rearchitecting involves a fundamental redesign of the application’s architecture to bring it in line with modern standards. This often necessitates the transformation of a monolithic application into microservices or adopting a new architectural pattern.

Pros: Rearchitecting offers advantages such as greater scalability, agility, and flexibility. It empowers organizations to leverage cloud-native technologies and embrace microservices architecture.

Cons: This strategy can be complex and resource-intensive, demanding a deep understanding and seamless integration of both legacy and modern technologies.

Retirement (sunsetting)

Description: In certain scenarios, it may prove more cost-effective to retire or sunset a legacy application, particularly if it no longer serves a purpose or if its functionality can be adequately replaced by off-the-shelf solutions or newer systems.

Pros: Retirement simplifies the IT landscape, reducing ongoing maintenance costs, and eliminating security risks associated with the legacy application.

Cons: Successful retirement may require meticulous data migration and careful planning to ensure a smooth transition for users.
Choose the strategy that aligns with your goals and resources.

Common Challenges in Legacy Application Migration

Legacy application migration is a complex process, especially when teams migrate legacy systems that have grown over the years. The main challenges usually look like this

• Hidden dependencies: Legacy systems often rely on undocumented jobs, shared databases, and “small” integrations that are easy to miss. With Glorium Technologies, the work starts with dependency mapping, then sequencing and cutover planning follow from that map
• Data migration complexity: Conflicting data sources, inconsistent data quality, and legacy data stored in outdated formats can lead to mismatches in the new system. In Glorium Technologies projects, data integrity checks and a clear data audit trail are set up early, before cutover
• Cutover risk and operational disruption: A big switch can interrupt business operations and increase data loss risk. Test migration waves, staged releases, and parallel runs help protect business continuity and keep rollback realistic
• Security and access drift: During cloud migration, temporary permissions tend to spread fast, and controls get inconsistent across cloud services. Clear guardrails, least privilege, and access reviews for each migration wave help prevent data security gaps
• Adoption and delivery friction: The new environment changes how teams deploy, monitor, and support systems. User acceptance testing should be treated as a real gate, with handover sessions so teams can operate the new system confidently
• Cost surprises after shift migration: Cloud infrastructure costs can rise if old sizing and data transfer patterns move “as is.” Glorium Technologies builds optimization into the migration plan with clear ownership, budgets, and measurable targets

Principles of Migrating Legacy Applications

The migration phase is a pivotal juncture in the legacy application migration process to cloud environment, demanding meticulous planning and execution.

Here’s a closer look at this critical stage:

Data cleanup

Data, often the lifeblood of an application, must be treated with precision and care. Data cleanup involves identifying and rectifying inconsistencies, redundancies, and inaccuracies within the already existing systems and data repositories. This cleansing process ensures that only relevant and accurate data is migrated, minimizing disruptions in the new, cloud infrastructure environment.

Compatibility checks

Compatibility is paramount during migrating legacy and applications to the cloud first. It entails assessing whether the existing and migrating legacy apps and software components, including software libraries, databases, and integrations, are compatible with the cloud migration target environment. Compatibility checks help identify potential roadblocks and the need for adjustments or upgrades to address during migrating legacy applications.

Execution in accordance with the plan

The private cloud migration plan, meticulously crafted during the planning phase, serves as the blueprint for the actual migration process. Following the cloud migration plan diligently is of paramount importance. It delineates the sequence of actions, timelines, and milestones. Deviations from the system migration plan should be well-documented and justified.

Progress monitoring

Constant vigilance is essential during legacy systems migration. Regularly monitor the progress of each migration task, cross-referencing it with the predefined timeline. Monitoring provides early detection of any deviations or complications, enabling timely intervention and corrective actions.

Step-by-Step Guide

• Identify the applications for migration. Review your portfolio to identify which applications should be moved to the cloud
• Evaluate cloud readiness. Assess the cloud readiness of each application, considering factors like architecture, data dependencies, and compatibility
• Define objectives and scope. Clearly outline your migration objectives, including performance goals, cost savings, and scalability
• Choose a cloud provider. Select a cloud provider based on your requirements, evaluating services offered, pricing, security, and compliance.

• Rehost (lift and shift): Move applications to the cloud without significant modification. Ideal for quick migrations with minimal risk.
• Refactor (repackage): Make minor modifications to the application to leverage cloud-native features and services.
• Rearchitect (redesign): Fundamentally alter the application’s architecture to fully embrace cloud capabilities, suitable for long-term agility and scalability.
• Replace (rebuild): Replace the existing application with a cloud-native solution.

• Define the target architecture: Establish the cloud architecture, including services and resources required.
• Data nigration strategy: Plan for migrating data securely and efficiently, ensuring data integrity and minimal downtime.
• Security and compliance: Implement security measures and ensure compliance with relevant regulations.

• Develop a migration plan: Create a detailed migration schedule, considering dependencies and potential risks.
• Pilot migration: Conduct a pilot migration with small applications to validate the process.
• Execute migration: Migrate applications according to the plan, monitoring closely for issues.

• Functional testing: Ensure the applications work as expected in the new environment.
• Performance testing: Evaluate the performance of applications to ensure they meet the desired benchmarks.
• Security testing: Conduct security tests to protect data in the cloud.

• Monitor performance: Regularly monitor application performance to identify and resolve any issues.
• Cost management: Keep track of cloud costs to optimize spending.
• Continual improvement: Improve applications to take advantage of new cloud features and technologies.

Security, Compliance, and Risk Considerations During Migration

Security and compliance should guide the migration process from day one, especially when sensitive data is involved. A practical approach usually includes a small set of controls that teams apply consistently across old and new systems

• Data classification and mapping: Identify valuable data, map its location across existing systems, and define the initial steps in the data migration process. This reduces blind spots and helps teams choose the right migration strategy
• Protection during data migration: Use encryption for data in motion and at rest, strong key management, and strict access controls for exports, backups, and cutover tooling. Keep temporary access short-lived and remove it as soon as the migration project phase ends
• Auditability and evidence: Preserve logs, approvals, change history, and a data audit trail that supports compliance reviews. This is critical when you move legacy applications that handle regulated workloads on cloud platforms
• Least privilege and blast radius control: Utilize segmentation, scoped credentials, and role-based access to mitigate the impact if something goes wrong. Avoid long-lived migration admin accounts that remain after system migration
• Continuous validation: Test backups, restore paths, monitoring, and rollback steps early and repeat them as needed. Security testing should run alongside performance checks and user acceptance testing, so risk is visible before cutover

Expert Insight

As a seasoned Project Manager with extensive experience in IT infrastructure and application migrations, I have overseen numerous legacy application transitions to cloud environments. Based on my experience, here are some key insights and recommendations for successfully managing such a migration:

1. Stakeholder engagement: Ensure that all relevant stakeholders, including IT staff, business unit leaders, and end-users, are engaged from the outset. Their input is invaluable in understanding the application’s intricacies and managing expectations.
2. Risk management: Legacy application migration comes with risks, including data loss, security vulnerabilities, and potential downtime. Identifying these risks early and planning mitigation strategies is vital for a smooth transition.
3. Training and knowledge transfer: One area that is often overlooked is the training and upskilling of your team. The cloud environment may introduce new tools and processes. Ensuring your team is prepared to manage and operate in the new environment is critical for long-term success.

Legacy Application Migration in a Nutshell

In essence, migrating a legacy application is a highly structured and technically intricate undertaking that demands meticulous attention to detail. By embracing data cleanup, compatibility checks, and dependency management, organizations can ensure a seamless transition of legacy apps to a modernized environment.

Legacy application migration is not just about modernizing your IT systems; it’s about future-proofing your whole business operations. Embrace the change, choose the right legacy applications migration options and path, and navigate the IT highway toward a brighter, more agile, and secure digital future.

How Glorium Technologies Helps You Reduce Migration Risk and Modernize Faster

Glorium Technologies runs legacy system migration as a structured delivery program, supported by proven quality and security practices, as certified by ISO 9001 and ISO 27001. We plan and execute cloud migration on primary cloud services, backed by AWS Select Tier Partner and Microsoft Silver Partner status.

We begin with discovery: inventory, dependency mapping, and a clear migration strategy. Then we create a detailed migration plan with staged cutovers, testing gates, and rollback steps. For data migration, we define the data migration process, validate data formats, reconcile legacy data, and track exceptions to protect data integrity. We test migration waves and monitor the system’s performance through the cutover window.

Glorium Technologies also brings delivery maturity and external credibility, including 150+ products delivered, multi-year recognition on Inc. 5000, IAOP Global Outsourcing 100, and Clutch Top 1000.
Reach out to us to book an intro call with Glorium Technologies to review your legacy system migration scope, risks, and next steps.

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