Introduction

If you’re preparing for a .NET Core interview in 2025, you need to be ready for both fundamental concepts and real-world scenarios.In this blog we’ll go through Mostly asked .NET Core interview questions. Interviewers often test your understanding of how .NET Core differs from .NET Framework, its cross-platform nature, and why it is the preferred choice for cloud-native and microservices applications.

Read this blog: What is .NET Core? Why Cross-Platform?

This exclusive guide from Logic Lense covers the Top 10 frequently asked .NET Core interview questions with detailed answers, tailored to help you crack your interview confidently.

10 Interview Questions & Answers

1. What are the key differences between .NET Framework and .NET Core?

Answer:

• Platform Support: .NET Framework is Windows-only, while .NET Core is cross-platform (Windows, Linux, macOS).

• Deployment: .NET Framework apps need system-wide installation; .NET Core apps support self-contained deployment.

• Performance: .NET Core offers better performance, modularity, and faster runtime execution.

• Open Source: .NET Core is fully open source under .NET Foundation.

• App Models: .NET Core supports modern workloads like microservices, cloud apps, and containers, unlike .NET Framework.

2. How does .NET Core achieve cross-platform compatibility?

Answer:

• Uses CoreCLR runtime and CoreFX library, both built to run across multiple OS.

• Provides a platform-agnostic compiler (Roslyn).

• Uses abstraction layers that handle OS-specific implementations.

• Enables developers to write once and run apps anywhere (.dll cross-OS execution).

3. What is the role of CoreCLR and CoreFX in .NET Core?

Answer:

• CoreCLR: The runtime engine that manages memory, JIT compilation, garbage collection, and code execution.

• CoreFX: A modular collection of libraries that provides APIs for networking, I/O, collections, and other functionality.
  Together, they form the foundation of .NET Core applications.

4. Why is .NET Core considered more suitable for microservices and cloud apps?

Answer:

• Lightweight and modular runtime.

• High scalability with Kestrel Web Server.

• Native support for Docker & Kubernetes.

• Integration with cloud providers (Azure, AWS, GCP).

• Supports gRPC, REST APIs, and event-driven systems, making it perfect for microservices.

5. Which companies or products use .NET Core in production?

Answer:

• Microsoft (Azure, Bing, Office Online)

• Stack Overflow

• Alibaba

• Siemens

• Samsung

• GoDaddy
  These examples prove .NET Core’s enterprise-grade reliability.

6. What are the advantages of .NET Core over Java for enterprise applications?

Answer:

• Better performance benchmarks in web APIs.

• Unified platform for web, mobile, desktop, and IoT.

• Easy integration with Azure services.

• Modern language features (C# 12, async streams, record types).

• Flexible deployment (self-contained apps vs JVM requirement).

7. Explain the concept of Kestrel in .NET Core.

Answer:

• Kestrel is the default cross-platform web server in ASP.NET Core.

• Built on libuv (and later System.IO Pipelines).

• Designed for high-performance HTTP request processing.

• Works independently or behind a reverse proxy like Nginx or IIS.

8. What is the difference between SDK and Runtime in .NET Core?

Answer:

• .NET Core SDK: Includes the runtime, libraries, CLI tools, and compilers for development.

• .NET Core Runtime: Only contains what is needed to run apps, not build them.
  👉 Developers install SDK, production servers typically only need the Runtime.

9. How does .NET Core handle backward compatibility?

Answer:

• Side-by-side versioning allows multiple app versions on the same machine.

• Applications can specify the runtime version they depend on in the configuration.

• Eliminates “DLL Hell” issues seen in .NET Framework.

10. What are the new features introduced in .NET 8 (latest version)?

Answer:

• Native AOT (Ahead-of-Time compilation) for faster startup.

• Improved Blazor with server-side & WebAssembly unification.

• Performance improvements in LINQ & JSON APIs.

• Unified platform with .NET MAUI for cross-device development.

• Cloud-native enhancements with better container support.

✅ Conclusion

.NET Core has transformed how developers build modern, scalable, and cross-platform applications. Whether you’re aiming for a role in cloud-native development, microservices, or enterprise systems, mastering these interview questions will give you an edge. Prepare these .NET Core interview Questions for your next interview.

Keep following Logic Lense for more .NET tutorials, interview prep guides, and coding insights to stay ahead in your career.

Before you go, here is your bonus for reading .NET Core interview questions:-  What is .NET Core? Why Cross-Platform?

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