IEntityService and then EntityService for each of my entities?Not necessarily for every entity — only if it makes sense.
Absolutely, yes. In fact, that’s expected in a Clean Architecture setup.
Examples:
ReportGenerationService that combines bookings, customers, and payments.TokenService for authentication tokens.CurrencyConversionService that hits an external API.NotificationService that sends emails or SMS.👉 As long as these services live in the Application Layer and follow dependency inversion (i.e., they depend only on interfaces, not implementations), you’re doing great.
| Aspect | Service | Repository |
|---|---|---|
| Layer | Application Layer | Domain Layer (interface), Infrastructure Layer (implementation) |
| Responsibility | Orchestrates business logic / use cases | Data access abstraction |
| Focus | Coordinates multiple domain/repo operations, validation, business flow | Fetching/storing data for a specific entity |
| Example | PlaceOrderService, ReportService |
ICustomerRepository, IOrderRepository |
init mean?init is an access modifier for properties that allows you to set a property only during object initialization, but not after.
class or record for DTOs in Clean Architecture?Use
recordfor DTOs when possible — it's clean, immutable by default, and semantically perfect for data transfer.
record is a great fit for DTOs| Feature | record |
class |
|---|---|---|
| Immutable by default | ✅ (with init) |
❌ (need manual setup) |
| Value-based equality | ✅ | ❌ (ref-based by default) |
| Concise syntax | ✅ | ❌ (more boilerplate) |
| Use for data containers | ✅ (perfect fit) | ✅ (but more verbose) |
| Custom behavior/logic | ❌ (less suitable) | ✅ (better for rich behavior) |
class?Use class if your DTO or model:
record)For example, in the Domain Layer (Entities, ValueObjects), you'll usually stick to
class— because that's where behavior lives.
Statelessness:
Resource Identification:
HTTP Methods:
Use of Standard Status Codes:
200 OK, 201 Created, 404 Not Found, 500 Internal Server Error).HATEOAS:
[ApiController]
[Route("api/[controller]")]
public class CustomerController : ControllerBase {
[HttpGet("{id}")]
public IActionResult GetCustomerById(int id) { /*...*/ }
[HttpGet]
public IActionResult GetAllCustomers() { /*...*/ }
[HttpGet("{id}/orders")]
public IActionResult GetCustomerOrders(int id) { /*...*/ }
}
C#Absolutely, let’s go over the main “list-like” data types in C#. They all serve similar purposes—holding multiple items—but differ in functionality, performance, and use cases. Here’s a detailed breakdown:
🔷 1. IEnumerable
Example:
IEnumerable<int> numbers = GetNumbers(); // Lazy-loaded maybe
foreach (var num in numbers)
Console.WriteLine(num);
💡 Ideal when:
🔷 2. ICollection
💡 Useful when:
🔷 3. IList
💡 Use when:
🔷 4. List
Example:
var list = new List<string>();
list.Add("One");
list.Add("Two");
var second = list[1]; // "Two"
💡 Go-to general purpose collection.
🔷 5. IReadOnlyCollection & IReadOnlyList
💡 Used when:
🔷 6. Array (T[])
Example:
int[] numbers = new int[5];
numbers[0] = 42;
💡 Great for performance-sensitive or fixed-size data.
🔷 7. ObservableCollection
💡 Use in UI apps when the view needs to react to collection changes.
🔷 8. HashSet
💡 Best for fast membership checking (contains x).
🔷 Summary Table
| Type | Indexing | Modifiable | Ordered | Duplicates | Use Case |
|---|---|---|---|---|---|
| IEnumerable | ❌ | ❌ | ✔️ | ✔️ | Basic read-only stream or LINQ chaining |
| ICollection | ❌ | ✔️ | ✔️ | ✔️ | Expose modifiable group of items |
| IList | ✔️ | ✔️ | ✔️ | ✔️ | Full-featured list abstraction |
| List | ✔️ | ✔️ | ✔️ | ✔️ | Standard go-to collection |
| IReadOnlyList | ✔️ | ❌ | ✔️ | ✔️ | Return data safely from service or repo |
| Array (T[]) | ✔️ | ✔️ | ✔️ | ✔️ | Fixed-size, performant indexing |
| ObservableCollection | ✔️ | ✔️ | ✔️ | ✔️ | UI binding for collections |
| HashSet | ❌ | ✔️ | ❌ | ❌ | Fast lookup, uniqueness enforcement |
—
If you tell me the scenario (e.g. search results, modifying a cart, populating a drop-down), I can recommend the best type for it. Want that?