Five Modern C# Features Every .NET Developer Should Know

Introduction

Building .NET backends—whether REST APIs or microservices—requires clean, maintainable code. With .NET 10 and C# 14, Microsoft continues its focus on reducing boilerplate and improving code readability. Many of these features are small on their own, but together they can significantly improve the developer experience.

Below are five features that I have found particularly useful, listed in order of priority.

1. Primary Constructors (Highest Priority)

For many developers, this is one of the most impactful language improvements in recent years.

Before

public class UserService
{
    private readonly DbContext _db;
    private readonly ILogger<UserService> _logger;
    
    public UserService(DbContext db, ILogger<UserService> logger)
    {
        _db = db;
        _logger = logger;
    }
}

With Primary Constructors

public class UserService(DbContext db, ILogger<UserService> logger)
{
    public async Task<User> GetById(int id)
    {
        return await db.Users.FindAsync(id);
    }
}

As you can observe, constructor parameters become available throughout the class without requiring explicit field declarations and assignments.

In dependency-injection-heavy applications, primary constructors can significantly reduce constructor boilerplate.

2. The field Keyword

Validating auto-implemented properties was painful in earlier versions of C#. A full getter/setter implementation was required just to access the backing field.

Before

public class Order
{
    private int _quantity;

    public int Quantity
    {
        get => _quantity;

        set
        {
            if (value < 0)
                throw new ArgumentException();

            _quantity = value;
        }
    }
}

With field

public class Order
{
    public int Quantity
    {
        get;
        set
        {
            if (value < 0)
                throw new ArgumentException();

            field = value;
        }
    }
}

As you can notice, there is no private field declaration. Just use field wherever the backing value is needed.

This is particularly useful when property validation is required but creating an explicit backing field feels unnecessary.

3. Record Types

Many applications still use classes for types whose primary purpose is to transport data. Records provide value-based equality by default, making them a natural fit for DTOs and API contracts.

Before

public class Employee
{
    public string Name { get; set; }
    public string Email { get; set; }
}

Using a Record

public record Employee(
    string Name,
    string Email
);

The same type can be expressed more concisely using a record.

Use records when the primary purpose of a type is to carry data. Records are particularly useful for DTOs, API request models, and response models where data representation is more important than object identity.

4. Pattern Matching Improvements

Pattern matching continues to become more expressive with each C# release.

Before

if (order != null &&
    order.Status == Status.Completed)
{
}

Now

if (order is { Status: Status.Completed })
{
}

Another Example

if (x is > 0 and < 100)
{
    // ...
}

Pattern matching enables more expressive and declarative conditions while reducing nested conditional logic.

5. Required Members

Modern C# introduces the required keyword:

public class Employee
{
    public required string Name { get; set; }

    public required string Email { get; set; }
}

Now, when creating an instance, the compiler expects these properties to be initialized.

var employee = new Employee
{
    Name = "John",
    Email = "[email protected]"
};

If a required property is omitted, the compiler generates a warning, helping catch initialization mistakes before the application runs.

When Should You Use These Features?

These features are especially valuable in:

• ASP.NET Core Web APIs

• Microservices architectures

• Minimal APIs

• Domain-driven design applications

• DTO and contract-heavy projects

• Dependency Injection-based applications

Adopting them gradually can reduce boilerplate while improving readability and maintainability across the codebase.

Conclusion

Modern C# continues to remove boilerplate while improving code clarity. The features discussed above help developers write cleaner and more maintainable applications.

Primary constructors simplify dependency injection scenarios, the field keyword reduces property boilerplate, records provide concise data models, pattern matching improves readability, and required members help enforce object initialization rules at compile time.

If you're modernizing a .NET 6 or .NET 8 codebase, these should be among the first features worth exploring.