.Net Web API questions for Experience professional

anand m

Hello All,

I am preparing for interview for Asp.net Web API questions, kindly please share me to cover below topics on any very Good sites in online to explore.

Need experience professional prepartion to crack interview in Web API , I am total 13 years in .Net.

I. Concepts wise questions and answers to crack the interview in Web API .

2. Any use cases to explore more for interview prospect.

Thanks

Anand.

5 Replies

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Tuhin Paul1y ago
Accepted answer
Some common real-world use cases that are likely to be discussed in interviews:

a. Creating a CRUD Application
- Implement a simple to-do application using Web API.
- Focus on different HTTP methods (GET, POST, PUT, DELETE) and status codes.
- Handle validation, error management, and responses.
b. File Upload and Download
- Build an API that allows file uploads (using MultipartFormDataContent).
- Check proper error handling, file size restrictions, and security measures.
- Create an endpoint for file downloads with caching mechanisms.
c. Implementing Rate Limiting
- Discuss and implement rate-limiting for a Web API to prevent abuse.
- Use in-memory caching or Redis for tracking API calls.
d. Authentication & Authorization with JWT
- Implement JWT-based authentication for a secure API.
- Discuss token expiration, refresh tokens, and securing endpoints.
- Integrate OAuth2 or OpenID Connect for third-party authentication.
e. Logging and Error Handling
- Use a logging framework like Serilog or NLog to log errors.
- Set up centralized logging (e.g., ELK Stack, Azure Application Insights).
- Implement custom error-handling middleware.
f. Caching Strategy
- Discuss various caching strategies (memory caching, distributed caching, response caching).
- Implement caching to optimize performance, including cache expiration and validation.
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Alex Stebliuk1y ago
Hello, Anand! With your .NET experience, diving into REST principles and API design is a great next step. For practical project ideas and real-world examples, check here—it could help solidify your understanding. Good luck! In light of your 13 years' experience with .NET, I recommend diving into Microsoft's official docs and blogs. Practical use cases can be found at sites such as StackOverflow and GitHub Discussions. In preparation for Web APIs, pay attention to REST principles, versioning, security, and error handling. Also, check out platforms like Pluralsight and Udemy for courses with real-world scenarios. Good luck!
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Tuhin Paul1y ago
1. Build full-fledged Web API services (CRUD operations, authentication, file upload/download, etc.) to demonstrate your skills.
2. As an experienced developer, you'll likely face system design questions. Be prepared to design scalable and maintainable Web APIs.
3. Do mock interviews with peers or on platforms like Pramp, Interviewing.io, or Exponent.
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Tuhin Paul1y ago
Key concepts you should master and the types of questions that may come up in an interview:

a. Basics of Web API
- What is Web API? How does it differ from WCF?
- Explain REST and RESTful services.
- What are HTTP methods used in Web API? (GET, POST, PUT, DELETE)
- What is routing in Web API? How does attribute routing work?
- How do you version a Web API?
Key Focus:
- Understand HTTP methods and their proper usage.
- Routing concepts, including conventional and attribute-based routing.
- Statutory issues such as statelessness and cache control.
b. Advanced Concepts
- What are Action Filters and how do you use them in Web API?
- What is Dependency Injection (DI) in Web API? How is it configured in .NET Core?
- How would you handle logging, exception handling, and performance monitoring in Web API?
- What is CORS and how do you handle it in Web API?
Key Focus:
- Dependency Injection with built-in DI container.
- Custom filters (Authorization, Action Filters, Exception Filters, etc.).
- Exception handling using middleware and global exception filters.
- CORS policy configuration and common scenarios.
c. Security
- What are the different ways to authenticate and authorize users in Web API?
- Explain OAuth and JWT in Web API security.
- What is Cross-Site Request Forgery (CSRF) and how can it be prevented in Web API?
- What are some best practices to secure Web API?
Key Focus:
- Authentication: Token-based (JWT, OAuth), Cookie-based.
- Authorization: Role-based and claims-based access control.
- CSRF, CORS, and handling attacks (like SQL Injection, XSS).
- Using HTTPS and SSL.
d. Data Handling and Serialization
- What is content negotiation?
- Explain how JSON and XML serialization works in Web API.
- What is the role of JsonResult and IActionResult?
- How do you handle large payloads in Web API?
Key Focus:
- Properly managing responses and formats (JSON, XML, etc.).
- Serialization techniques, custom formatters, and response handling.
- Considerations for working with large datasets and pagination.
e. Asynchronous Programming
- What is asynchronous programming and how do you use it in Web API?
- How do you handle async actions in Web API?
Key Focus:
- Implementing async and await for better scalability.
- Best practices for async API calls and I/O-bound tasks.
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Amira Bedhiafi1y ago
Here is a link to help you : 50 Asp.Net Web API Interview Questions and Answers (2025)
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