3 Strategies for .NET Modernization

It’s time to tackle the .NET modernization project. Microsoft released its .NET framework in 2002.  The Windows-dependent framework created an environment for developing ASP.NET web forms, web-based services, and applications. Two decades later, Microsoft announced:

  • Releases before 4.6.2 would no longer be supported as of April 2022.
  • .NET Framework 4.8 would be included in supported operating systems.
  • .NET Framework support would cease when the operating system (OS) was retired.

Because .NET framework ships with a Windows operating system (OS), Microsoft will not support a framework running on a discontinued OS. That doesn’t mean replacing or retiring legacy .NET Framework applications. Instead, .NET modernization is a viable alternative.

Microsoft has released an open-source version of .NET framework designed for cloud-based implementations. The open-source solution, referred to as  .NET, is a cross-platform solution. It leverages cloud security for improved protection and uses its scalability for added performance.


Why .NET Modernization?

Legacy .NET Framework applications use older technology that may not migrate to the cloud with a lift and shift strategy. Many older technologies lack the agility needed to live in the cloud. They don’t take advantage of modern technology’s use of containers or rely on microservice design.

Unfortunately, replacing a legacy application is not just a technical decision. Many .NET Framework installations are business-critical applications. These applications cannot be retired or replaced without significant investment in time, money, and staff resources. Keeping legacy technology constrains an organization’s ability to scale, maintain a strong cybersecurity posture, or meet business requirements.



.NET Framework applications were monolithic in design, making it difficult to scale. Even if scaling is isolated to a subroutine or module, the entire application must be scaled because of its structure. Large applications take more test time and can extend delivery dates.

On-premise solutions require hardware that must be purchased and maintained. With fluctuating workloads, organizations could purchase equipment only used to capacity five times a year. Cloud services can scale quickly to address peak periods and return to a base level when volumes drop.

Scalability gives organizations the agility they need to respond to changing business requirements. Not only does the cloud provide greater flexibility, but it also eliminates in-house support for equipment procurement and maintenance.



Every application has the potential for security flaws. Legacy applications have known security vulnerabilities, especially those functioning in a hybrid cloud environment. These flaws may not be addressed if the application has been retired.

Interdependencies may hamper security. Applications may not support multi-factor authentication (MFA) or maintain compliance-required security logs. Adding encryption capabilities to a .NET Framework may present challenges.

Some security requirements such as NIST 800-171, PCI, and GDPR have extensive standards to protect personal data. Legacy .NET applications may lack the architecture to comply. Or the methods to address the requirements pose added threats.

Cloud providers have built-in security features to address different compliance standards. For example, cloud service providers already have security in place to protect card and health data. These security services ensure organizations comply with applicable standards.


Customer Experience

Consumers have high expectations when it comes to customer experiences. Consumers want fast, responsive interactions. They do not want to wait or repeat themselves. If organizations do not have the technical capabilities to deliver unified omnichannel experiences, they will fall behind their competitors.

Legacy systems were not designed for speed. Many solutions trying to operate in today’s market struggle with high latency and slow performance, which leads to poor customer experiences. They may also use data formats that do not merge with systems designed for artificial intelligence or virtual reality.

As more companies follow Amazon’s business model, AI will become a must-have rather than a nice-to-have. Amazon has 40% of the eCommerce market, with Walmart following in second with 7%.

This gap directly results from Amazon’s recommendations based on its AI algorithms.

Businesses constrained by .NET Framework applications may be unable to meet customer expectations and deliver a superior experience. Legacy systems do not architected for data sharing and real-time access.


Business Requirements

Legacy .NET applications can limit an organization’s ability to meet customer expectations. Websites may run too slow, or applications can’t accommodate the latest features. Finding people with the skills to merge old and new technology can be lengthy and costly.

All of these factors contribute to companies being unable to meet business requirements. Their infrastructure moves too slowly to compete in the rush to meet customer expectations. Adding functionality to business applications takes too long to realize bottom-line benefits.

Businesses need to meet expectations, whether internal Wiki or external portals. Eliminating an internal Microsoft SQL Server database used for customer support isn’t workable. However, moving hundreds or thousands of web pages to another platform is too costly. Modernizing .NET Framework applications may be the right solution to meet business needs.


How to Begin .NET Modernization

With options such as containerization, organizations can pick the application modernization strategy that works for a given NET application. Before making commitments and establishing deadlines, companies should inventory their existing .NET applications. They should ask questions such as:

  • What functionality does the NET app provide?
  • How old is the code?
  • What production-level metrics must be met?
  • How is the current application deployed?
  • What are the configuration requirements?
  • Are there security, compliance, or audit standards?
  • How is the current application supported?

Answering these questions may require a multi-functional team, including third parties that interface with the application.


.NET Framework Application Example

Suppose IT developed a web-based expense reporting application using the .NET framework. The application linked expense items to the company’s policy for that expense. The report was sent to accounting for review and approval when the form was completed.

The code is old, as the programmer left the department five years ago. No one supported or maintained the application. Only critical bug fixes were addressed. The primary complaint was slow response times from remote staff traveling to customers or potential customer locations.

Employees access the application over the internet using a VPN client. The system resides on-premise behind the firewall. Latency has become more of an issue as more staff work remotely. Complaints have increased, with many citing poor error messaging as an obstacle to fixing the problem without IT support.

The application runs on a typical Windows Server stack starting with Apache. Support requests have increased significantly in the last 12 months. The increase could be related to increased users, degraded performance, or lack of reporting in earlier years.

Before moving to a strategy, ask the end-user about the application. What functionality is the application missing? Are they happy with its performance?  Is it easy to use? Answers to these questions can be crucial in determining the best modernization strategy.


Strategies for .NET Framework Modernization

.NET modernization has three strategic paths. The appropriate strategy depends on the state of the existing application, the available resources, and the business requirements.



Also known as lift and shift, rehosting is migrating the existing application to the cloud without modification. The application operates as it did on-premise; only it will be located on virtual machines in the cloud. The cloud would make the application easier to access, but it may not resolve performance issues.

If employees were dissatisfied with the existing NET application or wanted added functionality, rehosting may be a poor option. However, there may be operational constraints that make re-platforming or rearchitecting inadvisable.



Replatforming means running the application using cloud-managed services and technologies such as containers. This approach optimizes the application for the cloud without significant coding.

Replatforming a .NET Framework application using a Windows container keeps the application’s core architecture while accessing cloud services. These services would include Microsoft Azure SQL database, caching, monitoring and continuous deployment pipelines.

For the expense reporting .NET application, re-platforming could address some of the performance-related issues. Depending on the available resources, the application could be coded to take advantage of Microsoft Azure SQL cloud database management. This would also help with information retrieval.

Some minor changes to the application’s functionality could be included, but that is usually part of a rearchitecting strategy.



Rearchitecting is moving the application to the cloud. These would become cloud native apps and use microservice architecture. These features would allow for scaling and agility as a company’s needs change. This strategy requires a new application using best practices for writing cloud-native code.

This option is the most time-consuming and resource-intensive of the three strategies. It removes a monolithic structure that limits agility. It creates microservices that run separately within a container to reduce time to market.

Should the example expense reporting system be rearchitected? It’s an expensive option, but it may be worthwhile if the system is used extensively with more remote employees. It provides an opportunity to add functionality including using the Azure App Service. If the corporate goal is to become cloud-native, rearchitecting would be the final choice.


Strategic Phases

Some organizations look at app modernization as a phased strategy. They might rehost the expense reporting system today and schedule a rearchitecting for later. They might consider re-platforming as a contingency plan if performance becomes a problem.

Modernizing .NET applications requires careful planning and analysis. Without a defined strategy, companies can fall short of their transformation goals. With help from people with extensive knowledge of Microsoft technology, businesses can accomplish a successful .NET modernization. Contact us or read our blog to learn more.

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