Best Practices for Structuring Large-Scale ASP.NET Core Applications

Hey everyone!

As an ASP.NET Core Full-Stack Developer, I’ve been on a journey of learning and improving how large-scale applications should be structured. One of the most exciting parts of this journey has been working on ArcCare, the hospital management system. This project has challenged me to implement best practices that keep the codebase scalable, maintainable, and efficient.

I wanted to share some key takeaways from my experience so far. If you’re working on a big project or planning one, these insights might help!

1. Modular Architecture: Keep It Clean & Organized

When I started ArcCare, I knew it needed a strong foundation. I adopted Clean Architecture to separate different layers:

• Presentation Layer (Razor Pages/MVC): Handles the user interface.
• Application Layer: Manages business logic and services.
• Infrastructure Layer: Deals with database access and third-party integrations.
• Domain Layer: Contains the core business rules and entities.

This approach keeps everything well-structured and makes future updates much easier!

2. Interface-Repository-Service Pattern: Because Loose Coupling Matters

I quickly realized that tightly coupling services and data access would lead to chaos. That’s why ArcCare follows the Interface-Repository-Service Pattern:

• Interfaces define contracts for repositories and services.
• Repositories handle database interactions via Entity Framework Core.
• Services contain business logic and interact with repositories.

This makes the system flexible and easy to test. Plus, if I need to swap out a database or change the data structure, I can do it without breaking everything!

3. DI: Keep Things Manageable

ASP.NET Core makes dependency injection super easy, and I’ve used it extensively in ArcCare to manage:

• Authentication and Authorization
• Database Context (DbContext)
• Third-party services like email and payment gateways

This keeps my code clean and avoids unnecessary dependencies. If you’re not using DI in your projects, trust me—it’s a game-changer!

4. Entity Framework Core: Use It the Right Way

Since ArcCare relies on Entity Framework Core (EF Core), I’ve learned a few best practices:

• Use migrations to handle database changes smoothly.
• Implement the Repository Pattern to keep database access centralized.
• Use AsNoTracking() for read-heavy queries to improve performance.
• Handle transactions and concurrency to avoid data conflicts.

EF Core is powerful, but using it the right way is what makes a real difference!

5. CQRS (Command Query Responsibility Segregation): Keep Reads & Writes Separate

To improve efficiency, I’ve implemented CQRS in ArcCare:

• Commands handle write operations (Create, Update, Delete).
• Queries handle read operations separately.

This prevents unnecessary dependencies and makes database interactions smoother, which is crucial for a real-time system like ArcCare.

6. Security: Never an Afterthought!

Since ArcCare deals with sensitive hospital and patient data, security is a top priority. Some key measures I’ve implemented:

• ASP.NET Core Identity for authentication and role-based access control.
• JWT authentication for secure API interactions.
• Data encryption for protecting sensitive information.
• Rate-limiting and CORS policies to prevent attacks.

A healthcare system MUST be secure—there’s no compromise on this!

7. Logging, Monitoring, and Exception Handling

A well-monitored system means fewer surprises. Here’s what I’ve implemented in ArcCare:

• Serilog and Application Insights for detailed logging.
• Global Exception Handling Middleware to catch and log errors.
• Health checks to ensure system uptime and reliability.

Logging helps debug issues quickly, and monitoring ensures the system is running smoothly at all times.

8. Performance Optimization: Because Speed Matters!

For ArcCare, speed is critical, especially when handling real-time patient data. Here’s how I ensure optimal performance:

• In-Memory & Distributed Caching (Redis) for frequently accessed data.
• Async/Await in Services & Repositories to prevent blocking operations.
• Background services (hosted services) for handling scheduled tasks efficiently.

Performance optimization is something I’m constantly tweaking and improving!

Final Thoughts

Working on ArcCare has been an incredible learning experience. Building a large-scale ASP.NET Core application isn’t easy, but following structured best practices makes a huge difference. Whether you’re working on a hospital management system, an e-commerce platform, or any enterprise app, these principles will help you build something scalable and maintainable.

I’d love to hear your thoughts! Have you faced similar challenges while structuring your applications?

Let us have a conversation in the comments!