What Is ASP.NET and When to Choose It: Use Cases and Examples

With nearly 3,96 million live websites powered by ASP.NET, it’s clear that this Microsoft-backed framework remains a trusted choice for web development worldwide. Built on top of the .NET platform, ASP.NET adds a rich set of tools and libraries tailored for building modern, high-performance applications.

Thanks to its legacy footprint and long-standing enterprise adoption, the classic version of ASP.NET still holds a dominant 50.3% share of the web framework market. However, ASP.NET Core, the newest version of ASP.NET, is quickly becoming the framework of choice for new development.

In this article, we’ll take a closer look at how ASP.NET has evolved, examine its key strengths and limitations, and explore common use cases backed by real-life examples from successful projects.

But first, let’s define what stands behind ASP.NET.

ASP.NET is an open-source development framework created by Microsoft for building dynamic web applications and services with .NET. Because ASP.NET is part of the broader .NET ecosystem, developers benefit from access to a vast range of shared libraries, packages, and development tools.

Its modern version, ASP.NET Core, is actively developed as an open-source project on Microsoft’s dotnet/aspnetcore GitHub repository. This repository serves as a central hub for source code, community discussions, issue tracking, and contributions, with over 36,8k stars, thousands of forks, and a vibrant community behind it.

Beyond its core functionality, the ASP.NET ecosystem offers rich extensions for real-time communication (SignalR), performance monitoring, containerization with Docker and Kubernetes, and seamless integration with modern front-end frameworks.

Originally built as a part of the .NET Framework for Windows-based applications in the early 2000s, ASP.NET has undergone a significant transformation to meet the changing demands of modern web software development. Over more than two decades of development, ASP.NET has evolved to support multiple programming models, including Web Forms, MVC, Web API, and its modern, cross-platform successor, ASP.NET Core.

Let’s take a look at the major versions of ASP.NET and what they introduced.

Microsoft developed ASP.NET Web Forms in 2002 for rapid application development. Its event-driven model and drag-and-drop design approach made it exceptionally popular for building enterprise applications and internal business solutions.

With the evolution of the .NET ecosystem, Microsoft has placed ASP.NET Web Forms in maintenance mode. While it continues to receive essential security updates as part of .NET Framework 4.8, no new features are being developed. This means that companies relying on Web Forms can continue to operate their legacy systems without interruption, but the framework doesn’t focus on future innovations.

As the industry shifts toward modern frameworks (e.g., ASP.NET Core and Blazor), the pool of developers with deep expertise in Web Forms is gradually shrinking. Moreover, the Web Forms model relies on concepts like ViewState and postbacks, which can be at odds with modern development practices (such as containerization, microservices, and cloud-native architectures).

Released in 2009, ASP.NET MVC was introduced as an alternative to ASP.NET Web Forms. It promoted the Model-View-Controller design pattern, which separates an application into three main components, each with a distinct responsibility. This clear separation of concerns makes the application easier to maintain, extend, and test, especially in large or complex projects.

ASP.NET MVC moved away from the event-driven, stateful architecture of Web Forms. Instead, it emphasizes a stateless request/response model, encouraging better separation of concerns and more manageable, scalable codebases.

Although the rise of ASP.NET Core has shifted the focus of new projects, ASP.NET MVC still commands a strong legacy presence. According to BuiltWith, over 527,000 live websites are still using ASP.NET MVC, with an additional 1.25 million sites having used it historically. That’s a total of more than 1.78 million websites that have adopted the framework at some point. Still, today, many enterprise applications continue to run on ASP.NET MVC due to established codebases and developer expertise.

ASP.NET Web API, introduced as part of ASP.NET MVC 4 in 2012, made it easier for developers to create HTTP-based endpoints that could be accessed by a wide range of clients, including browsers, mobile apps, and IoT devices. It was specifically designed for building RESTful services that follow standard HTTP methods (GET, POST, PUT, DELETE), making the APIs more consistent, scalable, and easier to consume across platforms.

ASP.NET Web API follows a REST (Representational State Transfer) architectural style, giving developers more control over HTTP features (such as status codes, headers, and the request/response pipeline). This makes it highly suitable for building scalable and standardized APIs.

While still widely used in legacy systems running on the full .NET Framework, ASP.NET Web API is in a maintenance state. Microsoft continues to offer security and compatibility updates but has shifted major innovation efforts to ASP.NET Core.

Originally introduced as ASP.NET vNext, the framework was rebranded as ASP.NET Core and officially released in June 2016. ASP.NET Core unified previously separate models, combining the strengths of ASP.NET MVC and ASP.NET Web API into a single, cohesive programming model. Unlike its predecessors, ASP.NET Core was designed to run seamlessly on Windows, macOS, and Linux. This cross-platform capability, paired with its open-source nature, has paved the way for broader adoption and community contributions.

According to the latest Stack Overflow Survey, 19.1% of professional developers are using ASP.NET Core, which places it among the top five most used web frameworks and web technologies. Worth noting that 72% of developers expressed admiration for ASP.NET Core.

The framework employs a modular design that allows developers to add only the components necessary for their specific app. This results in leaner applications with faster startup times. The built-in middleware pipeline provides a clear, manageable structure for handling HTTP requests and responses. ASP.NET Core uses the Kestrel web server, a lightweight, high-performance server that meets today’s high-throughput demands. Its architecture emphasizes asynchronous processing and dependency injection, both of which enhance scalability and make testing easier.

ASP.NET Core also includes Blazor for building richly interactive web UI, and it integrates with other popular front-end JavaScript frameworks like Angular, React, Vue.js, and Bootstrap. Simplified configuration, side-by-side versioning, and integration with modern development tools (like Visual Studio and Visual Studio Code) contribute to a smoother development experience. These features allow developers to focus more on business logic rather than on boilerplate code and environmental constraints.

If you’re starting a new project today, ASP.NET Core is the recommended choice, since ASP.NET no longer receives updates. So we’ll further concentrate on what ASP.NET Core can bring to the table.

ASP.NET Core offers a range of powerful features designed to meet the needs of today’s fast-paced web development environment. Below is an in-depth look at its core features and the advantages they can bring to your business.

ASP.NET Core is fully cross-platform, meaning developers can build and run applications on Windows, Linux, and macOS. This flexibility is one of the key differentiators from the classic ASP.NET Framework, which was traditionally tied to Windows. With ASP.NET Core, teams can use their preferred development environments and target a broader range of deployment options without being locked into a single operating system.

In terms of hosting, ASP.NET Core supports a wide variety of environments. Applications can run on Kestrel, be reverse-proxied through web servers like Nginx or Apache, or be hosted within Docker containers for more scalable and portable deployments. This makes ASP.NET Core an ideal fit for modern cloud-native architectures as well as hybrid or on-premises infrastructures.

For businesses, this cross-platform capability means lower infrastructure costs, easier CI/CD integration, and more flexibility in adapting to evolving technical requirements.

ASP.NET Core is engineered for speed. It uses a modular middleware pipeline and supports asynchronous programming out of the box. The independent TechEmpower benchmarks show ASP.NET Core among the fastest web frameworks available today. The framework also efficiently uses memory and processing power, which makes it well-suited for high-traffic applications.

The framework’s ability to handle thousands of concurrent requests makes it ideal for growing businesses and customer-facing platforms that demand scalability. This means that you can serve more users with fewer resources, which can help reduce infrastructure costs.

ASP.NET Core has built-in support for dependency injection, a design pattern that promotes loosely coupled, testable, and maintainable code. This feature is deeply integrated into the framework, making it easier to implement a clean software architecture from the start.

Dependency injection makes your codebase easier to modify, test, and scale. It encourages best practices in software design, reduces bugs, and speeds up development cycles. With a skillful ASP.NET web development company at your side, this feature can help you build a codebase that can evolve with your business needs and reduce long-term maintenance costs in the future.

ASP.NET Core introduces a unified development model that merges what were previously separate frameworks into a single, coherent framework:

• MVC for structured web applications
• Web API for RESTful services
• Razor Pages for page-focused scenarios

This consolidation means you no longer have to choose between different frameworks or combine several of them in one application. Instead of switching contexts or dealing with duplicate configurations, developers can use one consistent set of tools, conventions, and middleware to build all layers of a modern web application. Whether you’re building a dynamic web interface, exposing data through APIs, or rendering content server-side, ASP.NET Core handles it all within the same project structure.

For development teams, this unified model means simpler project architecture, reduced boilerplate code, and a shorter learning curve for new team members. From a business perspective, this translates into faster time-to-market and lower long-term maintenance costs.

Security is built into ASP.NET Core from the ground up. The framework includes features for authentication (including Identity, OAuth, OpenID Connect), authorization, HTTPS enforcement, and protection against threats like Cross-Site Scripting (XSS), Cross-Site Request Forgery (CSRF), and SQL Injection.

ASP.NET Core provides the tools to build secure applications by default, helping you meet industry compliance standards (such as GDPR, HIPAA, or PCI DSS) and protect user data. This is especially crucial for finance, healthcare, and e-commerce businesses.

Out-of-the-box support for environment-based configuration, dependency injection, built-in logging, and telemetry makes ASP.NET Core a natural fit for platforms like Microsoft Azure, AWS, and Google Cloud. For instance, the framework simplifies integration with cloud services such as Azure App Services, Azure Key Vault, Application Insights, and AWS Lambda. ASP.NET Core also supports health checks, metrics, and structured logging, which are essential for monitoring application performance and maintaining high system reliability in production.

In addition, ASP.NET Core is fully container-friendly. It works seamlessly with Docker and orchestration tools like Kubernetes, which makes it easy to package, deploy, and scale applications across environments.

For businesses building SaaS products or enterprise systems, these cloud and container capabilities offer substantial advantages:

• Elastic scalability to handle variable load
• High availability to minimize downtime
• Fault tolerance
• Simplified CI/CD pipelines that shorten the time between development and release

In essence, ASP.NET Core empowers organizations to build resilient, cloud-native applications that evolve quickly and scale efficiently.

ASP.NET Core is fully open-source and backed by Microsoft, with development conducted openly on GitHub. It benefits from a large and active global .NET community with over 100,000 contributions and 3,700 companies. With this active participation from the community, the framework remains modern, secure, and aligned with real-world development needs.

For businesses, this strong community backing ensures that ASP.NET Core remains well-supported and future-proof. It also means access to a broad talent pool, community-built tools and libraries, and rapid issue resolution.

ASP.NET Core supports Razor Pages, which simplifies page-focused web app development, and Blazor, which allows developers to build interactive client-side apps using C# instead of JavaScript. Blazor supports both server-side and WebAssembly-based models.

You can create responsive, modern web interfaces without relying heavily on JavaScript frameworks. This is especially beneficial for teams with deep .NET expertise, as it enables them to deliver polished front-end experiences without expanding the tech stack. It also makes it easier to share code between client and server, reducing development effort and ensuring consistency.

While ASP.NET Core offers many advantages, it’s not without its challenges.

Like any other web development framework, ASP.NET has its weak sides that can affect adoption, development speed, or compatibility in certain scenarios. However, understanding these constraints early allows you and your ASP.NET developers to plan ahead and minimize bottlenecks.

Below, we explore the most common limitations of ASP.NET Core and share practical strategies to overcome them.

Moving from classic ASP.NET (e.g., Web Forms) to ASP.NET Core isn’t a direct upgrade. It often requires significant code rewriting due to differences in architecture and APIs. Because ASP.NET Core is not a direct continuation of classic Web Forms, porting older systems often involves architectural changes and code rewrites.

To reduce risk and disruption, many companies opt for a phased migration strategy. Instead of rewriting everything at once, teams modernize high-priority modules first and gradually transition the rest of the system. Microsoft’s .NET Upgrade Assistant is a helpful tool that automates parts of this process and provides guidance throughout the migration journey.

Performance is a core strength of ASP.NET Core, but unlocking its full potential can require expertise in asynchronous programming, memory management, and optimization techniques. For businesses building high-traffic APIs or real-time systems, it’s important to assess performance early in the development process.

Tools like Application Insights and JetBrains dotTrace can help identify bottlenecks, while Microsoft’s official guidelines offer best practices for tuning performance. Partnering with experienced .NET developers can also accelerate this process and ensure applications are both fast and efficient.

Despite being cross-platform and open-source, ASP.NET Core is often perceived as tightly coupled with the Microsoft ecosystem, which may concern teams preferring open tooling or non-Windows environments.

A common misconception is that ASP.NET Core is heavily tied to the Microsoft ecosystem. While it was originally rooted in Windows development, ASP.NET Core has evolved into a fully open-source, cross-platform framework that runs seamlessly on Linux, macOS, and in containerized environments like Docker.

ASP.NET Core is a versatile, high-performance framework well-suited for building modern web applications across various industries. Below are key scenarios where choosing ASP.NET Core makes strategic sense. We support each use case with real-world examples from Leobit’s experience developing ASP.NET-powered applications.

ASP.NET Core is ideal for creating SaaS applications that need to serve multiple tenants, handle complex user permissions, and scale with growing demand. Its modular architecture, built-in support for dependency injection, and seamless integration with cloud platforms like Azure make it a go-to choice for SaaS products.

The franchise operations SaaS platform created by Leobit leverages ASP.NET Core for back-end services. It includes dynamic modules for franchisee management, reporting, and performance tracking, and supports a growing number of tenants across different regions.

We also used ASP.NET Core to support multiple user roles, recurring billing, and a comprehensive API when developing a full-cycle gym management subscription-based platform.

When you need a single codebase that supports multiple platforms (e.g., web, mobile, and desktop), ASP.NET Core, particularly when used with .NET MAUI or Blazor, enables efficient code sharing and consistent user experiences.

A great example of this in practice is Leobit’s work on a cross-platform concert ticketing platform. The team used ASP.NET Core together with .NET MAUI and Blazor to create native-like experiences for web, iOS, and Android. Thanks to the shared codebase, our developers achieved an impressive 90% code reuse, which significantly reduced development time and costs.

Despite supporting high user volumes and frequent real-time updates, the platform maintains excellent performance and stability. Today, it successfully manages thousands of ticket sales, check-ins, and live updates during peak event times.

Thanks to ASP.NET Core’s robust Identity system, the framework allows developers to define detailed user roles and permissions. Middleware support enables custom logic at every stage of request handling, which makes it easy to enforce security policies, logging, and data validation. Additionally, seamless integration with Azure services, such as Active Directory, Key Vault, and Azure Blob Storage, enables you to build secure, scalable, and cloud-native applications that support sensitive data and complex operations.

A prime example of this capability is Leobit’s HealthTech externship coordination platform, built with ASP.NET Core and Azure. Designed for a highly regulated healthcare environment, the platform supports multi-role access for administrators, healthcare providers, and students. It includes AI-based student-hospital matching, document upload and sharing, e-signatures, real-time status tracking, and detailed audit trails.

ASP.NET Core supports high-throughput APIs and scalable microservices, which make it ideal for serving real-time dashboards, processing event streams, or powering reporting engines. Its compatibility with platforms like Google BigQuery, Azure Synapse, or Apache Kafka allows for flexible, cloud-native data architectures. You can use these capabilities to generate actionable insights at scale while maintaining fast load times and responsive user experiences.

One example is Leobit’s work on modernizing a real estate platform’s data architecture. Using ASP.NET Web API in combination with Google BigQuery, the team overhauled the system to support near real-time analytics across multiple property categories and user roles. The solution enabled users to query large datasets quickly, visualize trends, and make timely decisions, which significantly improved the platform’s value proposition.

In another case, Leobit developed a re-commerce reporting portal with a back end powered by ASP.NET Core. This solution processes extensive datasets related to secondhand product transactions and presents the information in clear, interactive dashboards. The platform handles complex reporting logic, supports custom filters, and offers data visualizations tailored to business stakeholders.

ASP.NET Core can be a great choice for building responsive, high-performing web applications that involve secure transactions, user authentication, and integration with payment services. The framework offers out-of-the-box support for authentication and authorization, including integration with OAuth, OpenID Connect, and external identity providers like Google, Facebook, or Microsoft.

With ASP.NET Core Identity, developers can securely implement features like two-factor authentication, password recovery, and user role management. Additionally, its middleware architecture allows for customization of request handling pipelines, which helps to optimize security and performance.

A great example of these capabilities is Leobit’s printed photo ordering application, built using ASP.NET Core. The application allows users to customize their photo prints, place orders, and complete payments through a seamless and secure interface. It supports dynamic product handling, secure payment processing, and order tracking.

Another case is Leobit’s work on an enterprise B2B jewelry network — a secure, e-commerce-like platform tailored for jewelry wholesalers. It enables wholesalers to manage large inventories, connect with partners, and complete orders through an intuitive and robust digital interface. Built with ASP.NET Core, the platform maintains high security standards suitable for enterprise-level financial transactions.

With built-in support for encryption, authentication protocols, and data protection, ASP.NET Core helps development teams meet fintech compliance requirements such as PCI-DSS and GDPR. Its middleware pipeline allows fine-grained control over request processing and authentication workflows, so that financial data is transmitted securely. Moreover, ASP.NET Core supports asynchronous programming and parallel processing, which are essential for handling large volumes of real-time payment transactions.

Leobit used these ASP.NET Core’s capabilities when developing an alternative electronic payment SaaS solution. The application handles high-frequency transactions with ease, supports secure user authentication, and processes financial data in real time.

Another example is Leobit’s project for a global payment processing provider, where ASP.NET Core was used to create a secure back end. The platform integrates with multiple external payment gateways to enable seamless and automated financial workflows across different currencies and regions. With ASP.NET Core, the development team ensured smooth API interactions, high availability, and robust error handling. It helped our customer minimize transaction failures and deliver a seamless user experience for merchants and customers alike.

Real estate and proptech platforms often need to manage large datasets, integrate with third-party financial and legal systems, and support high-stakes transactions. ASP.NET Core is well-suited for these complex requirements due to its high performance, modular design, and robust integration capabilities. Its support for scalable back-end architectures, secure data handling, and cloud-native features makes it a good choice for building sophisticated real estate platforms.

A great example is Leobit’s work on a blockchain-based real estate platform, which combined ASP.NET Core with decentralized technologies to enable secure property transactions and enhanced transparency in real estate investments. The integration of blockchain added trust and auditability to the buying process, while ASP.NET Core handled key back-end services, business logic, and user management. This hybrid architecture helped reduce fraud risk and improved investor confidence by making property data and transactions more verifiable and tamper-proof.

In another project, Leobit developed a real estate solution that uses ASP.NET Core to automate complex financial calculations and help users better understand the financial impact of property investments. The platform streamlines compliance processes and improves the overall user experience by providing instant tax forecasts, personalized investment insights, and automated documentation.

Leobit brings over a decade of experience in building scalable, secure, and high-performing applications with ASP.NET. With more than 70 successful ASP.NET projects delivered across industries like fintech, real estate, and healthcare, we know how to tailor solutions to meet both technical and business needs.

As a Microsoft Solutions Partner for Digital & App Innovation, Leobit is trusted for delivering modern web solutions using the latest Microsoft technologies. Our team includes 78 Microsoft-certified engineers with hands-on expertise in ASP.NET Core, Blazor, MVC, and cloud-native development. We have also been recognized as a Top ASP.NET Development Company by Clutch on a global level and in Ukraine.

We support the full application development lifecycle, from architecture design and UI/UX to testing, deployment, and post-launch maintenance. Whether you’re building a new product or modernizing an existing one, we can ensure quality, scalability, and on-time delivery.

ASP.NET, and particularly its modern iteration ASP.NET Core, has proven to be a powerful and flexible framework for building robust, scalable, and secure web applications. Over the past two decades, it has evolved from a Windows-only solution into a fully cross-platform framework that runs on Linux, macOS, and Windows. While older versions like Web Forms and classic MVC are still supported, they are now considered legacy technologies in favor of ASP.NET Core.

Despite common misconceptions, ASP.NET Core works seamlessly in non-Microsoft environments. It supports deployment on Linux servers and integrates easily with open DevOps tools like GitHub Actions, Jenkins, and Docker, which make it a strong fit for modern development stacks.

Still, choosing ASP.NET should depend on your project’s specific needs, such as cross-platform support, maintainability, or enterprise-grade security. With the right development partner, you can fully use ASP.NET’s strengths while effectively addressing its challenges. Contact us to find out how we can help bring your vision to life with ASP.NET.