Serverless with Minimal APIs in .NET: Productivity and Scalability in the Same Package

Introduction to Serverless with Minimal APIs

The concept of serverless has gained prominence in recent years, especially with the adoption of architectures based on microservices and the need for scalability. The microservices approach allows dividing an application into independent services focused on specific responsibilities, which facilitates maintenance, technological evolution, and individual scalability of each component (SABBAG FILHO, 2025). Additionally, it allows teams to work autonomously on isolated features, speeding up deliveries and facilitating the adoption of DevOps practices and continuous integration. .NET, with its new features, especially Minimal APIs, enhances this scenario by enabling the construction of lightweight, dynamic, and highly productive applications (LOCK, 2023). This approach is interesting for serverless and microservices-based environments. In this article, we will explore how to combine these technologies to create scalable, resilient, and efficient solutions.

Concept of Minimal APIs

Minimal APIs, introduced in .NET, are a simplified way to develop RESTful APIs. They allow developers to write less code while maintaining clarity and efficiency (LOCK, 2023). The idea is to create endpoints quickly and minimally, without the need to configure complex controllers or models. This approach not only accelerates the development process but also reduces the complexity of the codebase, making it easier to understand and maintain.

Reasons to Use Minimal APIs

In addition to simplicity, Minimal APIs provide other advantages that make them an attractive choice for developers. Some of these advantages include:

• Less Code: The reduced amount of code needed to create an API makes development faster and more efficient.
• Ease of Testing: With fewer layers of abstraction, testing becomes simpler and more straightforward.
• Flexibility: Developers have the freedom to structure their code in a way that best suits their needs.

Concept of Serverless

Serverless is a cloud computing model that eliminates the need for explicit server management, allowing developers to focus exclusively on the code and functionalities of the application (PANDEY et al., 2023). This model ensures automatic scalability, lower operational maintenance, and a cost-effective approach based on actual usage.

Advantages of Serverless

The serverless model offers several advantages, such as:

• Automatic Scalability: Serverless applications can automatically scale with demand, eliminating concerns about server capacity. This means that during peak loads, the infrastructure adjusts automatically to maintain performance.
• Cost Reduction: You only pay for what you use, which can result in significant savings compared to dedicated servers. This is especially advantageous for startups and small projects.
• Less Maintenance: The infrastructure is managed by the cloud provider, allowing teams to focus on development and innovation rather than worrying about server administration.
• Rapid Deployments: Development time is reduced, allowing resources to be allocated to new features and improvements instead of maintenance.

Considerations of Serverless with Minimal APIs

By adopting a serverless architecture using Azure Functions combined with Minimal APIs, developers can publish highly efficient and scalable solutions with minimal complexity. The application written with Minimal APIs in .NET is encapsulated in functions that are triggered on demand, eliminating the need for manual server provisioning or continuous infrastructure management.

The deployment process is simplified: after developing the application in a minimalist framework, the code can be packaged and published directly to Azure via CI/CD pipelines or tools like the Azure CLI. This results in a solution that combines the lightweight and agility of Minimal APIs with the robustness and automatic scalability of the serverless environment, allowing teams to focus more on business logic than on operational details.

This type of architecture favors modern development practices such as DevOps and the implementation of microservices, promoting agility, lower coupling, and ease of maintenance in distributed systems.

Setting Up a .NET Project with Minimal APIs

To start creating a Minimal API in .NET, you need to have the .NET 6 SDK or higher installed. Below is an example of how to initialize a project:

dotnet new web -n MinimalApiExample

After creating the project, you can open the Program.cs file and define your endpoints. Here is a basic example:

using Microsoft.AspNetCore.Builder;
using Microsoft.Extensions.DependencyInjection;

var builder = WebApplication.CreateBuilder(args);
var app = builder.Build();

app.MapGet("/hello", () => "Hello, World!");

app.Run();

Integrating with Azure Functions

One of the most popular ways to implement serverless applications is by using Azure Functions. With Azure Functions, you can easily host your Minimal APIs and take advantage of Azure's scalability. Here is an example of how you can integrate a Minimal API with Azure Functions:

[FunctionName("HelloFunction")]
public static async Task<IActionResult> Run(
    [HttpTrigger(AuthorizationLevel.Function, "get", Route = null)] HttpRequest req,
    ILogger log)
{
    log.LogInformation("C# HTTP trigger function processed a request.");
    return new OkObjectResult("Hello from Azure Functions!");
}

Managing Dependencies

Managing dependencies is crucial in applications. With Minimal APIs, you can use dependency injection in a simplified way. Here’s how to inject a service into your Minimal API:

public interface IMyService
{
    string GetData();
}

public class MyService : IMyService
{
    public string GetData() => "Data from MyService";
}

var builder = WebApplication.CreateBuilder(args);
builder.Services.AddSingleton<IMyService, MyService>();

var app = builder.Build();

app.MapGet("/data", (IMyService myService) => myService.GetData());

app.Run();

Error Handling in Minimal APIs

It is essential to ensure that your API handles errors appropriately. Minimal APIs allow you to implement middleware for exception handling simply. Here’s an example of how you can do this:

app.Use(async (context, next) => 
{
    try
    {
        await next();
    }
    catch (Exception ex)
    {
        context.Response.StatusCode = 500;
        await context.Response.WriteAsync($"Internal Server Error: {ex.Message}");
    }
});

Monitoring and Logging

Monitoring is essential for maintaining applications in production. .NET supports Serilog and Application Insights, which can be easily integrated. This allows you to have a detailed view of your application’s performance and quickly identify issues. Here’s how to configure logging:

builder.Services.AddLogging(logging => 
{
    logging.AddConsole();
    logging.AddDebug();
});

builder.Services.AddApplicationInsightsTelemetry();

Performance Optimization

Performance is a critical aspect of serverless applications. Some best practices include:

• Minimizing the deployment package size: This can be done by removing unnecessary dependencies and using minification tools.
• Avoiding unnecessary network calls: Whenever possible, seek to optimize your API calls and use cached data.
• Using caching whenever possible: This may include using Redis or in-memory caching to speed up data retrieval.

Challenges and Considerations

Although the combination of serverless and Minimal APIs offers many benefits, it is important to be aware of some challenges and considerations:

• Runtime Limitations: Serverless functions typically have a maximum execution time, which can be an issue for longer operations.
• State Management: Serverless applications are inherently stateless, which can complicate the management of user sessions and temporary data.
• Monitoring and Debugging: Monitoring serverless applications can be more complex due to the distributed nature of the services.

Conclusion

Combining the serverless model with Minimal APIs in .NET is a powerful strategy for developing scalable and high-productivity applications. With the simplicity of Minimal APIs and the flexibility of serverless, developers can focus on what really matters: building solutions that meet business needs. Adopting these technologies can lead to a significant improvement in development efficiency and application performance. When considering the implementation of Minimal APIs in a serverless environment, it is essential to evaluate the specific needs of the project and prepare for the challenges that may arise along the way.