ASP.NET Web API Using Repositories and Service Layers
ASP.NET Web API is a powerful framework for building HTTP services that reach a broad range of clients including browsers, mobile devices, and IoT devices. To design scalable and maintainable applications, it is essential to use design patterns and architectural techniques that separate concerns and encapsulate logic. One such approach is to use the Repository and Service Layer patterns. This article delves into the implementation of ASP.NET Web API with Repositories and Service Layers, explaining the concepts in detail and highlighting important information.
What are Repositories and Service Layers?
Repository Pattern:
- Definition: The Repository pattern is a design pattern used to abstract and encapsulate data access logic. It mediates between the domain and data mapping layers using a collection-like interface for accessing domain objects.
- Primary Benefits:
- Separation of Concerns: Data access logic is isolated from business logic.
- Testability: Easier to write unit tests as the data access code can be mocked.
- Maintainability: Changes in the data store (e.g., changing from SQL Server to MongoDB) can be done with minimal impact on the rest of the application.
Service Layer:
- Definition: The Service Layer is responsible for encapsulating business logic. It acts as a façade that exposes operations to the presentation layer and coordinates actions between multiple repository operations.
- Primary Benefits:
- Business Logic Encapsulation: Centralizes business operations and rules.
- Reusability: Services can be reused by different clients or even different UIs.
- Scalability: Business logic can be scaled independently of UI or data access layers.
Implementation in ASP.NET Web API
Let’s consider a simple example of an e-commerce application with entities like Product.
Entities:
- Define the data model using Entity Framework Code First.
public class Product { public int Id { get; set; } public string Name { get; set; } public decimal Price { get; set; } public string Description { get; set; } }Repository Pattern:
- Interface for repository, defining standard CRUD operations.
public interface IRepository<T> { IEnumerable<T> GetAll(); T GetById(int id); void Add(T entity); void Update(T entity); void Delete(T entity); void Save(); }- Concrete implementation of the repository using Entity Framework.
public class ProductRepository : IRepository<Product> { private readonly ApplicationDbContext _context; public ProductRepository(ApplicationDbContext context) { _context = context; } public IEnumerable<Product> GetAll() { return _context.Products.ToList(); } public Product GetById(int id) { return _context.Products.Find(id); } public void Add(Product product) { _context.Products.Add(product); Save(); } public void Update(Product product) { _context.Entry(product).State = EntityState.Modified; Save(); } public void Delete(Product product) { _context.Products.Remove(product); Save(); } public void Save() { _context.SaveChanges(); } }Service Layer:
- Interface for the service layer.
public interface IProductService { IEnumerable<Product> GetAllProducts(); Product GetProductById(int id); void AddProduct(Product product); void UpdateProduct(Product product); void DeleteProduct(int id); }- Concrete service class for handling business logic.
public class ProductService : IProductService { private readonly IRepository<Product> _productRepository; public ProductService(IRepository<Product> productRepository) { _productRepository = productRepository; } public IEnumerable<Product> GetAllProducts() { return _productRepository.GetAll(); } public Product GetProductById(int id) { return _productRepository.GetById(id); } public void AddProduct(Product product) { _productRepository.Add(product); } public void UpdateProduct(Product product) { _productRepository.Update(product); } public void DeleteProduct(int id) { var product = _productRepository.GetById(id); if (product != null) { _productRepository.Delete(product); } } }ASP.NET Web API Controller:
- Using the service layer to delegate business logic.
public class ProductsController : ApiController { private readonly IProductService _productService; public ProductsController(IProductService productService) { _productService = productService; } [HttpGet] public IEnumerable<Product> GetProducts() { return _productService.GetAllProducts(); } [HttpGet] public IHttpActionResult GetProduct(int id) { var product = _productService.GetProductById(id); if (product == null) { return NotFound(); } return Ok(product); } [HttpPost] public void AddProduct([FromBody] Product product) { _productService.AddProduct(product); } [HttpPut] public void UpdateProduct(int id, [FromBody] Product product) { _productService.UpdateProduct(product); } [HttpDelete] public void DeleteProduct(int id) { _productService.DeleteProduct(id); } }Dependency Injection:
- Use a DI framework (like Ninject, Autofac, or Microsoft.Extensions.DependencyInjection in .NET Core) to manage dependencies.
services.AddScoped<ApplicationDbContext>(); services.AddScoped<IRepository<Product>, ProductRepository>(); services.AddScoped<IProductService, ProductService>();
Conclusion
Using Repositories and Service Layers in ASP.NET Web API results in a clean, maintainable, and testable codebase. The separation of concerns allows developers to manage and scale different parts of the application independently, leading to more robust and scalable solutions. Implementing these patterns effectively ensures that the application adheres to best practices, making it easier to maintain and extend over time.
By employing the Repository pattern for data access and the Service Layer for business logic, developers can ensure their ASP.NET Web API applications are structured properly, facilitating easier maintenance and scalability.
ASP.NET Web API Using Repositories and Service Layers: A Beginner's Guide
Creating a robust and maintainable ASP.NET Web API using the Repository and Service Layer patterns is a critical step towards building scalable and testable applications. This guide will walk you through the process step-by-step, from setting up the project to understanding the data flow, ensuring a clear understanding of each component.
Step 1: Setting Up the Project
Create a New ASP.NET Web API Project:
- Open Visual Studio and select 'Create a new project.'
- Choose 'ASP.NET Core Web Application' and click 'Next.'
- Name your project, choose a suitable location, and then click 'Create.'
- In the next window, select the 'API' template and click 'Create.'
Install Required Packages:
- Use NuGet Package Manager to add any necessary packages. For repository patterns, Entity Framework Core will be widely used.
Install-Package Microsoft.EntityFrameworkCore Install-Package Microsoft.EntityFrameworkCore.SqlServer Install-Package Microsoft.EntityFrameworkCore.Tools
Step 2: Define Models
Models represent the data entities that your application will work with. Let's define a simple model Product as an example.
public class Product
{
public int Id { get; set; }
public string Name { get; set; }
public string Category { get; set; }
public decimal Price { get; set; }
}
Step 3: Setting Up the Database Context
The DbContext class is the central piece for working with a database using Entity Framework Core.
using Microsoft.EntityFrameworkCore;
public class ProductContext : DbContext
{
public ProductContext(DbContextOptions<ProductContext> options) : base(options) { }
public DbSet<Product> Products { get; set; }
}
Step 4: Configure the Database Connection
In appsettings.json, add the connection string for your database. Replace the Data Source and Initial Catalog with your database details.
"ConnectionStrings": {
"DefaultConnection": "Server=(localdb)\\mssqllocaldb;Database=ProductDB;Trusted_Connection=True;MultipleActiveResultSets=true"
}
In Startup.cs or Program.cs (depending on your ASP.NET Core version), configure the services to use Entity Framework Core and the SQLite database.
public void ConfigureServices(IServiceCollection services)
{
services.AddDbContext<ProductContext>(options =>
options.UseSqlServer(Configuration.GetConnectionString("DefaultConnection")));
services.AddControllers();
}
Step 5: Implement the Repository Pattern
The Repository pattern helps to abstract data access code from the business logic.
- Define an Interface for the Repository:
public interface IProductRepository
{
IEnumerable<Product> GetAllProducts();
Product GetProductById(int id);
void InsertProduct(Product product);
void DeleteProduct(int id);
void UpdateProduct(Product product);
void Save();
}
- Implement the Repository:
public class ProductRepository : IProductRepository
{
private readonly ProductContext _context;
public ProductRepository(ProductContext context)
{
_context = context;
}
public IEnumerable<Product> GetAllProducts()
{
return _context.Products.ToList();
}
public Product GetProductById(int id)
{
return _context.Products.Find(id);
}
public void InsertProduct(Product product)
{
_context.Products.Add(product);
}
public void DeleteProduct(int id)
{
Product product = _context.Products.Find(id);
if (product != null)
{
_context.Products.Remove(product);
}
}
public void UpdateProduct(Product product)
{
_context.Entry(product).State = EntityState.Modified;
}
public void Save()
{
_context.SaveChanges();
}
}
Step 6: Implement the Service Layer
The Service Layer is responsible for business logic, it acts as an intermediary between the Repository and the Controller.
- Define Interface for the Service Layer:
public interface IProductService
{
IEnumerable<Product> GetProducts();
Product GetProduct(int id);
void AddProduct(Product product);
void RemoveProduct(int id);
void UpdateProduct(Product product);
}
- Implement the Service:
public class ProductService : IProductService
{
private readonly IProductRepository _productRepository;
public ProductService(IProductRepository productRepository)
{
_productRepository = productRepository;
}
public IEnumerable<Product> GetProducts()
{
return _productRepository.GetAllProducts();
}
public Product GetProduct(int id)
{
return _productRepository.GetProductById(id);
}
public void AddProduct(Product product)
{
if (product == null)
{
throw new ArgumentNullException(nameof(product));
}
_productRepository.InsertProduct(product);
_productRepository.Save();
}
public void RemoveProduct(int id)
{
var product = _productRepository.GetProductById(id);
if (product != null)
{
_productRepository.DeleteProduct(id);
_productRepository.Save();
}
}
public void UpdateProduct(Product product)
{
_productRepository.UpdateProduct(product);
_productRepository.Save();
}
}
Step 7: Register Services in DI Container
Register the service and repository with the dependency injection container in Startup.cs or Program.cs.
public void ConfigureServices(IServiceCollection services)
{
services.AddDbContext<ProductContext>(options =>
options.UseSqlServer(Configuration.GetConnectionString("DefaultConnection")));
services.AddScoped<IProductRepository, ProductRepository>();
services.AddScoped<IProductService, ProductService>();
services.AddControllers();
}
Step 8: Create the Controller
The Controller acts as the entry point for client requests and interacts with the Service layer to perform necessary actions.
[ApiController]
[Route("api/[controller]")]
public class ProductsController : ControllerBase
{
private readonly IProductService _productService;
public ProductsController(IProductService productService)
{
_productService = productService;
}
[HttpGet]
public IEnumerable<Product> GetProducts()
{
return _productService.GetProducts();
}
[HttpGet("{id}")]
public Product GetProduct(int id)
{
return _productService.GetProduct(id);
}
[HttpPost]
public void AddProduct([FromBody] Product product)
{
_productService.AddProduct(product);
}
[HttpPut]
public void UpdateProduct([FromBody] Product product)
{
_productService.UpdateProduct(product);
}
[HttpDelete("{id}")]
public void RemoveProduct(int id)
{
_productService.RemoveProduct(id);
}
}
Step 9: Run the Application
Ensure your database is configured correctly. If using a Local DB, you can create the initial migration and then update the database:
Add-Migration InitialCreate
Update-Database
Now, you can run your application. Test your API endpoints with tools like Postman or cURL to ensure everything is functioning as expected.
Data Flow Summary
- HTTP Request: A request is made to the controller.
- Controller Action: The controller method is invoked, which interacts with the service layer.
- Service Layer: Business logic is processed, and the repository is called to perform data operations.
- Repository: CRUD operations are performed on the database.
- Response: Results from the database operations are sent back through the service layer and controller, forming the response to the client.
By following these steps, you can build a maintainable and testable ASP.NET Web API using Repository and Service Layer patterns. This architecture not only modularizes the code but also makes it easier to manage and scale your application.
Top 10 Questions and Answers on ASP.NET Web API Using Repositories and Service Layers
1. What is ASP.NET Web API, and how does it differ from ASP.NET MVC?
ASP.NET Web API is a part of Microsoft's ASP.NET framework specifically designed for building HTTP services that can reach a broad range of clients including browsers and mobile devices. It emphasizes HTTP and supports REST-style architecture.
In contrast, ASP.NET MVC (Model-View-Controller) is a framework used for developing web applications that are highly testable, maintainable, and support separation of concerns using the MVC pattern. MVC is primarily used for applications that require complex user interfaces and interaction, such as traditional web applications.
The main difference lies in their focus: ASP.NET Web API is specialized for building APIs that serve as a communication layer for web services, whereas ASP.NET MVC is geared towards developing interactive, rich web applications.
2. Can you explain the role of the Repository and Service Layer in ASP.NET Web API?
Repository Layer: This layer is responsible for data access logic. It abstracts the data access process between the business logic (service layer) and the data source (e.g., database). This abstraction allows for the easy change of data sources (e.g., from SQL to NoSQL) without altering the service layer or the API logic. It typically involves interfaces that define the data operations (such as CRUD operations) and their implementations.
Service Layer: This layer contains the business logic. It coordinates the flow of data between the Repository layer and the Presentation layer (Web API). It handles business rules, validations, and interactions with the repository to perform operations. The service layer acts as an intermediary between the API and the data layer, ensuring that data manipulation adheres to business requirements.
Together, these layers ensure a clean separation of concerns, making the code more manageable, scalable, and maintainable.
3. How do you implement Dependency Injection in ASP.NET Web API for Repositories and Service Layers?
Dependency Injection (DI) is a software design pattern in which an object’s dependencies (i.e., the objects it works with) are provided to it externally rather than being created internally. In the context of ASP.NET Web API, DI can be used to inject services and repositories into controllers, simplifying testing and adhering to the SOLID principles, particularly the Dependency Inversion Principle.
To implement DI in ASP.NET Core Web API, follow these steps:
Define Interface and Implementation for Repository and Service:
public interface IProductRepository { IEnumerable<Product> GetAll(); Product GetById(int id); void Add(Product product); void Update(Product product); void Delete(int id); } public class ProductRepository : IProductRepository { private readonly ApplicationDbContext _context; public ProductRepository(ApplicationDbContext context) { _context = context; } public IEnumerable<Product> GetAll() => _context.Products; public Product GetById(int id) => _context.Products.Find(id); public void Add(Product product) => _context.Products.Add(product); public void Update(Product product) => _context.Products.Update(product); public void Delete(int id) => _context.Products.Remove(_context.Products.Find(id)); }Register Services in Startup.cs:
public void ConfigureServices(IServiceCollection services) { services.AddDbContext<ApplicationDbContext>(options => options.UseSqlServer(Configuration.GetConnectionString("DefaultConnection"))); services.AddScoped<IProductRepository, ProductRepository>(); services.AddScoped<IProductService, ProductService>(); services.AddControllers(); }Inject Services into Controllers:
[ApiController] [Route("api/[controller]")] public class ProductsController : ControllerBase { private readonly IProductService _service; public ProductsController(IProductService service) { _service = service; } [HttpGet] public IEnumerable<Product> Get() { return _service.GetAll(); } [HttpGet("{id}")] public IActionResult Get(int id) { var product = _service.GetById(id); if (product == null) return NotFound(); return Ok(product); } [HttpPost] public IActionResult Post(Product product) { _service.Add(product); return CreatedAtAction(nameof(Get), new { id = product.Id }, product); } [HttpPut("{id}")] public IActionResult Put(int id, Product product) { if (id != product.Id) return BadRequest(); _service.Update(product); return NoContent(); } [HttpDelete("{id}")] public IActionResult Delete(int id) { var product = _service.GetById(id); if (product == null) return NotFound(); _service.Delete(id); return NoContent(); } }
4. What are the benefits of using the Repository and Service Layers in ASP.NET Web API?
- Separation of Concerns: The repository layer handles data access, while the service layer manages business logic. This separation makes the codebase more organized and easier to manage.
- Testability: Unit tests can be written for the service layer without the need to involve the database. This results in faster and more reliable testing.
- Maintainability: Changes to data access, business logic, or the application's architecture can be made with minimal impact on other parts of the application.
- Reusability: Repository and service classes can be reused across different controllers or even different projects.
- Flexibility: The application can be adapted to different data sources with minimal changes to the business logic layer.
- Scalability: The architecture supports scaling by allowing different layers to be developed and managed independently.
5. How do you handle business rules and validations in the Service Layer?
In the service layer, business rules and validations are typically handled through various mechanisms such as validation frameworks, custom business logic, and validation attributes. Here’s an example of how you might implement these in a service layer:
Using Data Annotations:
public class Product : IValidatableObject { public int Id { get; set; } [Required] [StringLength(100, MinimumLength = 3)] public string Name { get; set; } [Range(0, double.MaxValue)] public decimal Price { get; set; } public IEnumerable<ValidationResult> Validate(ValidationContext validationContext) { if (Price < 10 && String.IsNullOrEmpty(Name)) { yield return new ValidationResult("Name is required if price is less than 10.", new[] { "Name" }); } } }Using FluentValidation:
public class ProductValidator : AbstractValidator<Product> { public ProductValidator() { RuleFor(p => p.Name) .NotEmpty().WithMessage("Name is required.") .Length(3, 100).WithMessage("Name length must be between 3 and 100 characters."); RuleFor(p => p.Price) .GreaterThanOrEqualTo(0).WithMessage("Price must be non-negative"); } } public class ProductService { private readonly IProductRepository _repository; private readonly ProductValidator _validator; public ProductService(IProductRepository repository, ProductValidator validator) { _repository = repository; _validator = validator; } public bool Add(Product product) { var results = _validator.Validate(product); if (!results.IsValid) { throw new ValidationException(results.Errors); } _repository.Add(product); return true; } }Custom Methods:
You can also implement custom validation logic directly within your service layer methods.
6. How do you handle exceptions in ASP.NET Web API with Repository and Service Layers?
Proper exception handling is crucial for building robust and reliable applications. Here’s how you can handle exceptions in ASP.NET Web API with repository and service layers:
Define Custom Exceptions:
public class ProductNotFoundException : Exception { public ProductNotFoundException(int productId) : base($"Product with ID {productId} not found.") { } }Throw Custom Exceptions in the Service Layer:
public class ProductService { private readonly IProductRepository _repository; public ProductService(IProductRepository repository) { _repository = repository; } public Product GetById(int id) { var product = _repository.GetById(id); if (product == null) { throw new ProductNotFoundException(id); } return product; } public void Delete(int id) { var product = _repository.GetById(id); if (product == null) { throw new ProductNotFoundException(id); } _repository.Delete(id); } }Handle Exceptions in Controllers:
public class ProductsController : ControllerBase { private readonly IProductService _service; public ProductsController(IProductService service) { _service = service; } [HttpGet("{id}")] public IActionResult Get(int id) { try { var product = _service.GetById(id); return Ok(product); } catch (ProductNotFoundException ex) { return NotFound(ex.Message); } } [HttpDelete("{id}")] public IActionResult Delete(int id) { try { _service.Delete(id); return NoContent(); } catch (ProductNotFoundException ex) { return NotFound(ex.Message); } } }Use Exception Filters for Global Exception Handling:
public class ApiExceptionFilterAttribute : ExceptionFilterAttribute { private readonly ILogger<ApiExceptionFilterAttribute> _logger; public ApiExceptionFilterAttribute(ILogger<ApiExceptionFilterAttribute> logger) { _logger = logger; } public override void OnException(ExceptionContext context) { _logger.LogError("Exception caught: {Message}", context.Exception.Message); var response = new { ErrorCode = context.Exception.HResult, ErrorMessage = context.Exception.Message, StackTrace = context.Exception.StackTrace // Consider not sending this in production }; context.Result = new JsonResult(response) { StatusCode = StatusCodes.Status500InternalServerError }; } } public void ConfigureServices(IServiceCollection services) { services.AddControllers(options => options.Filters.Add(typeof(ApiExceptionFilterAttribute))); // Other configurations }
7. How do you implement a unit of work pattern in ASP.NET Web API?
The Unit of Work pattern is a design pattern that maintains a list of business operations during a transaction and coordinates the writing out of changes and resolution of concurrency problems. It helps to encapsulate a transaction and ensure that all changes are committed or rolled back atomically.
Here’s how you can implement the Unit of Work pattern in ASP.NET Web API with repository and service layers:
Define the Unit of Work Interface:
public interface IUnitOfWork : IDisposable { IProductRepository Products { get; } int Complete(); }Implement the Unit of Work:
public class UnitOfWork : IUnitOfWork { private readonly ApplicationDbContext _context; private IProductRepository _productRepository; public UnitOfWork(ApplicationDbContext context) { _context = context; } public IProductRepository Products { get { return _productRepository ??= new ProductRepository(_context); } } public int Complete() { return _context.SaveChanges(); } public void Dispose() { _context.Dispose(); } }Register Unit of Work in Startup.cs:
public void ConfigureServices(IServiceCollection services) { services.AddDbContext<ApplicationDbContext>(options => options.UseSqlServer(Configuration.GetConnectionString("DefaultConnection"))); services.AddScoped<IUnitOfWork, UnitOfWork>(); services.AddControllers(); }Use Unit of Work in Service Layer:
public class ProductService { private readonly IUnitOfWork _unitOfWork; public ProductService(IUnitOfWork unitOfWork) { _unitOfWork = unitOfWork; } public void Add(Product product) { _unitOfWork.Products.Add(product); _unitOfWork.Complete(); } public void Update(Product product) { _unitOfWork.Products.Update(product); _unitOfWork.Complete(); } public void Delete(int id) { _unitOfWork.Products.Delete(id); _unitOfWork.Complete(); } }
8. How do you ensure data consistency and integrity in ASP.NET Web API?
Ensuring data consistency and integrity in ASP.NET Web API involves several strategies, including using transactions, validation, and enforcing business rules.
Database Transactions:
Using the Unit of Work pattern, you can ensure that all operations within a transaction are committed together or rolled back if any operation fails.
Validation:
Perform validation both on the client-side and server-side to ensure that data is correct and adheres to business rules before it is processed by the API.
Business Rules:
Implement business rules in the service layer to enforce constraints and ensure that the data remains consistent and valid throughout the application’s lifecycle.
Optimistic Concurrency:
Implement optimistic concurrency control using ETag headers or timestamps to handle concurrent updates and avoid conflicts.
Foreign Key Constraints:
Use foreign key constraints in the database schema to maintain referential integrity.
Stored Procedures:
Use stored procedures for complex operations that require multiple steps to ensure atomicity.
9. How do you implement logging in ASP.NET Web API with Repository and Service Layers?
Logging is essential for monitoring the application's behavior, diagnosing errors, and auditing actions. Here's how you can implement logging in ASP.NET Web API with repository and service layers:
Register Logging in Startup.cs:
ASP.NET Core provides built-in logging services. You can add logging providers in
Startup.cs:public void ConfigureServices(IServiceCollection services) { services.AddControllers(); // Configure logging providers services.AddLogging(loggingBuilder => { loggingBuilder.AddConsole(); loggingBuilder.AddDebug(); loggingBuilder.AddEventSourceLogger(); }); }Inject ILogger into Service Layer:
public class ProductService { private readonly IProductRepository _repository; private readonly ILogger<ProductService> _logger; public ProductService(IProductRepository repository, ILogger<ProductService> logger) { _repository = repository; _logger = logger; } public Product GetById(int id) { _logger.LogInformation("Getting product by ID: {Id}", id); var product = _repository.GetById(id); if (product == null) { _logger.LogWarning("Product not found for ID: {Id}", id); } return product; } public void Add(Product product) { _logger.LogInformation("Adding new product: {Name}, {Price}", product.Name, product.Price); _repository.Add(product); _logger.LogInformation("Product added, ID: {Id}", product.Id); } }Configure Logging Levels and Output in appsettings.json:
{ "Logging": { "LogLevel": { "Default": "Information", "Microsoft": "Warning", "Microsoft.Hosting.Lifetime": "Information" } }, "AllowedHosts": "*" }Custom Logging Providers:
You can create custom logging providers to log messages to different destinations such as databases, text files, or external logging services.
10. How do you implement caching in ASP.NET Web API?
Caching can significantly improve the performance of an ASP.NET Web API by reducing the need to repeatedly fetch data from the database or other external sources. Here’s how you can implement caching in ASP.NET Web API:
Register MemoryCache in Startup.cs:
ASP.NET Core provides built-in support for caching using
IMemoryCache. You can register it inStartup.cs:public void ConfigureServices(IServiceCollection services) { services.AddControllers(); // Register memory cache services.AddMemoryCache(); }Inject IMemoryCache into Service Layer:
public class ProductService { private readonly IProductRepository _repository; private readonly ILogger<ProductService> _logger; private readonly IMemoryCache _cache; public ProductService(IProductRepository repository, ILogger<ProductService> logger, IMemoryCache cache) { _repository = repository; _logger = logger; _cache = cache; } public Product GetById(int id) { // Define cache key var cacheKey = $"product_{id}"; // Try to retrieve product from cache if (_cache.TryGetValue(cacheKey, out Product product)) { _logger.LogInformation("Product retrieved from cache, ID: {Id}", id); return product; } // If not in cache, retrieve from database product = _repository.GetById(id); if (product == null) { _logger.LogWarning("Product not found for ID: {Id}", id); return null; } // Store product in cache for 1 hour var cacheEntryOptions = new MemoryCacheEntryOptions() .SetSlidingExpiration(TimeSpan.FromHours(1)); _cache.Set(cacheKey, product, cacheEntryOptions); _logger.LogInformation("Product stored in cache, ID: {Id}", id); return product; } }Distributed Caching:
For scalable applications, consider using distributed caching options such as Redis or SQL Server distributed caching.
By following these guidelines, you can build robust, scalable, and maintainable ASP.NET Web APIs using repositories and service layers. This architecture not only separates concerns effectively but also provides a solid foundation for future enhancements and modifications.