Moving a Legacy App to the Cloud

Last Updated:
November 8, 2023

Moving a Legacy App to the Cloud

Transitioning a legacy Windows® application to a Software as a Service (SaaS) model involves multiple steps to ensure a smooth migration process and an outcome that retains existing customers and attracts new customers. While the specifics of this process will depend on your application’s unique characteristics and requirements, this post will describe at a high level the steps you need to take to be successful.

Assessment and Planning

Transition Driver

What is driving the move to SaaS? Are your primary competitors using a SaaS model? Have you lost customers to SaaS products? Are your customers requesting the move? Do you plan to expand into new regions or markets where SaaS-ifying your application will improve your chances for success? Are you having technical issues that could be addressed with a SaaS model? Understanding the factors driving the move will help you retain focus on your desired outcome during planning, execution, and post-migration optimization and support.

Perform a SWOT (Strengths, Weaknesses, Opportunities, Threats) Analysis

Theoretically, IT should be able to transition the application to SaaS from a technical perspective—but does the project make sense for the business? Include representation from groups outside of IT, including sales, support, marketing, and finance. Engagement with groups across the organization will prevent the SWOT analysis from focusing solely on technical considerations and drive the corporate cultural shift that needs to happen to truly support the transition.

Conduct an Application Inventory

Identify and document all the components of your legacy application, including databases, servers, dependencies, APIs, and configurations. Understanding exactly what needs to be moved or updated will help you more accurately assess the time, budget, and expertise needed to complete the project.

Determine the Deployment Model

What model do you want to adopt for the SaaS-fied application? Assuming that the application is currently delivered to users from the corporate data center (i.e., a private cloud), what model will make the most sense for the application, the business, and customers—a public, hybrid, or multi-cloud model? (NOTE: to learn more about cloud deployment models, see the Windows ISV Hosting Options post.)

Assess Public Cloud Choices

Which cloud platform best fits your application, business, economic, security, compliance, and customer needs? Major cloud platforms include Amazon® Web Services (AWS), Microsoft® Azure®, Google Cloud™, and Oracle® Cloud Infrastructure.

Assess Existing IT Team Skill Set and Availability

Do your team members have the expertise and bandwidth to plan, manage, and execute the technical transition on their own? Can you train your existing team? How much time and budget does that training add to the project? Do you plan to hire employees to fill the experience gaps, or do you need to engage with one or more consulting firms? Once the move is made, does your existing team have the expertise and bandwidth to manage the application in its new location, or do you want to engage a managed service provider (MSP)?

Cost and Time Analysis

Estimate the potential costs and time investment of moving and running your application in the cloud, including company personnel, outside services, your application compatibility with the cloud, application refactoring and rearchitecting, API updates, data transfer, storage compute costs, consulting, and tools to ensure security and monitor application performance. Additionally, what solution do you plan to use to deliver your Windows application to customers from your chosen cloud provider, and how does that choice impact the timeframe and budget?

Assess Potential Cloud Platforms

The major cloud platforms offer free versions of their service to prospects for evaluation and testing, provided you stay within certain usage parameters. If you’re working with an MSP, they may have access to more extensive test environments than those provided for free. And, if your application is subject to market or regulatory compliance, you will want to test drive the security and compliance capabilities offered by each cloud platform.

Evaluate Application Delivery Solutions

How are you going to provide customer access to your Windows application? Are you going to publish it or virtualize it? Which solutions will work with your cloud platform choice? Do your customers utilize a wide variety of devices to access and use your application? Do your customers expect easy log ins and low latency, even over low bandwidth networks? Do you need access control and authentication capabilities like MFA and SSO? Do you want simple and cost-effective pricing? GO-Global securely publishes Windows applications from any cloud to users located anywhere using any device, works on any cloud service, and provides a great customer experience even on low-bandwidth networks. It’s an easy application delivery choice that will reduce migration complexity.

Application Refactoring

Check Compatibility with the New Platform

Analyze the application's code and dependencies to identify any components that may need to be updated or modified to work in a cloud environment. Depending on your assessment, you may need to re-architect parts of the application to take full advantage of cloud-native features like scalability, auto-scaling, and serverless computing.

Dependency Management

Update and manage application dependencies to ensure they are compatible with the cloud platform and won't cause issues during deployment.

Application Database

If your application uses a database, assess whether you should migrate to a cloud database service or ensure your on-premises database can be accessed securely from the cloud.

Application Scalability

If needed, modify your application to be able to scale horizontally to handle increased load using cloud-native scaling features and load balancers.

Cost Containment

Can you modify your application to use computing resources more efficiently to save on cloud costs? For example, can you maximize your app’s memory management efficiency, release resources that are no longer needed, and optimize UI responsiveness and external dependencies? Will these improvements be significant enough to make an appreciable difference in your cloud costs?

Document Everything

Maintain comprehensive documentation regarding application refactoring that includes architecture diagrams, configuration details, and deployment procedures for your cloud-ready Windows application.

Data Migration and Application Deployment

Setup your Cloud Environment

Working with your MSP or cloud provider, provision your infrastructure. Set up networking, storage, servers, load balancing, and any other required services. Implement access control and identity management functions.

Test, Test, Test

Thoroughly test your application in your chosen cloud environment to ensure that it functions as expected and can handle the expected loads. Pay attention to compatibility and performance. Perform load testing to determine how your application performs under various levels of stress and load to help you fine-tune scalability settings. Determine the strategy for scaling your application up or down and test that, too. Finally, ensure your application and cloud infrastructure is as secure as possible by conducting penetration testing, vulnerability testing, software security testing, data security testing, etc.

Develop Customer Training and Onboarding Resources

Build training and onboarding resources to prepare existing customers for the transition to the cloud application. This can include written documentation, webinars, or in-person training sessions for larger customers. Offer training in a variety of media so customers can engage with the type most appealing to them. Build new customer onboarding materials and processes for the new application in parallel with existing customer training development.

Plan Your Application Deployment.

Determine how you want to deploy your application to existing customers, for example:

  • Canary deployment/Gradual rollout: Initially, release the cloud application to a small group of trusted customers or a limited geographic region. If the application performs well without critical issues, gradually expand its availability to a subset of existing customers so you can monitor the application's performance and user feedback before a full-scale rollout.
  • Phased deployment: Divide your customer base into segments (for example, regional, level of experience with the app, number of years as a customer). Deploy the application to one group at a time, ensuring that any issues are identified and resolved before moving to the next group.
  • Customer Opt-in: Allow existing customers to opt-in or request access to the new cloud application. This approach gives customers control over their migration to the new system. Provide a generous timeframe for customers to move to the new application, but be prepared to enforce a hard deadline for customers dragging their feet.
  • New customers: determine a date when new customers will automatically onboard to the cloud application.
  • Partner with your helpdesk team: Ask your helpdesk team for input on the rollout plan prior to informing customers.They may have helpful insights regarding customer expectations and behavior that will improve rollout execution and customer success. And of course provide them with the final rollout timeline so they can be prepared to assist customers having issues with the cloud application.

Communicate with Customers Early and Often

Inform customers of the cloud application launch 3-4 months in advance. The announcement should cover application changes, deployment timeline, and what actions are expected from customers. If your using a gradual or phased deployment approach, align announcements and information with the timeline for each customer segment. Provide a feedback loop for customers to prevent your helpdesk team from being overwhelmed and to address issues before they escalate.

Data Backup and Recovery

Your application data should be securely backed up prior to migration. Create a backup and disaster recovery plan using your new cloud services. Ensure that your data is regularly backed up and can be restored quickly in case of failure, and schedule regular backup and data recovery procedure testing.

Data Transfer to the Cloud

Move your application's data to the cloud using appropriate tools and services. This might involve using database migration tools, storage services, or data transfer appliances. Most cloud providers offer database services that simplify this process.

Execute the Rollout while Maintaining the Old System in Parallel

Run the old system in parallel with the cloud application during the transition period. This allows users to switch back if issues arise and provides a safety net during the migration.

Post Deployment

Logging and Monitoring

Implement comprehensive logging and monitoring solutions and practices, using cloud-native tools or third-party services. This helps you gain visibility into application performance and allows you to make the best use of your new cloud resources.

Compliance and Security Auditing

Regularly audit and ensure compliance with security and governance policies, and make necessary adjustments as needed.

Cost Management

Monitor and manage costs by optimizing resource utilization and using cloud cost management tools provided by your chosen cloud platform and/or your MSP.

Scalability and Growth Planning

Plan for future growth and scalability, considering potential changes in user demand and application requirements.


Careful and thorough planning is fundamental to successfully moving your legacy Windows application to the cloud. Consider working with cloud migration experts or consultants, if necessary, to ensure a successful transition.

One way to ease your workload is to choose GO-Global as your application delivery tool. Because GO-Global works with any cloud infrastructure, you can chose the cloud service that works best for you without worrying about how you are going to deliver your application.

To learn more:

·       Read GO-Global customer case studies here;

·       Request a demo here;

·       Or, download a free 30-day trial.