Wipro .net Interview Questions

.NET, MVC, SQL Server & WCF Interview Questions – 2025

Are you preparing for a .NET developer interview in 2025? Whether you're a fresher or an experienced programmer, this detailed list of interview questions and topic summaries across C#.NET, ASP.NET, MVC, SQL Server, and WCF will help sharpen your skills.

These questions are based on real-time enterprise projects and reflect the latest industry expectations in software development roles.

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💻 C#.NET & ASP.NET Interview Questions

• What is a delegate, and where have you used it in real-time projects?
  Delegates are object-oriented pointers to methods. They are used in event handling and callback mechanisms, often in WinForms, background threading, or middleware layers.
• How do you improve the performance of an ASP.NET webpage?
  Techniques include output caching, view state optimization, bundling & minification, using async/await, lazy loading, reducing HTTP requests, and SQL query tuning.
• What are the types of validations in ASP.NET and how are they implemented?
  Client-side (JavaScript/jQuery) and server-side (RequiredFieldValidator, CompareValidator, RangeValidator, etc.). You can also use Regular Expressions or custom validators.
• Explain the architecture of ASP.NET.
  It includes browser-client, web server (IIS), page life cycle, code-behind logic, and application pipeline via HTTP modules and handlers.
• What is the purpose of generics in C#?
  Generics provide type safety and reduce runtime casting. They are widely used in collections, repositories, and custom utility methods.
• What are static classes and static fields used for in C#?
  Static classes cannot be instantiated. They’re useful for utility functions. Static fields store values shared across all instances of a class.
• What is the difference between ref and out in C#?
  Both allow passing parameters by reference. ref requires initialization before passing, while out must be assigned inside the method.
• What is boxing and unboxing?
  Boxing converts a value type to an object type. Unboxing extracts the value type from the object. It affects performance due to heap allocation.

🧩 ASP.NET MVC Interview Questions

• Explain the MVC architecture.
  Model-View-Controller separates concerns. Models handle data, Views handle UI, and Controllers process user input. This enables testability and clean design.
• How are validations implemented in ASP.NET MVC?
  Using Data Annotations like [Required], [Range], [EmailAddress] and with client-side jQuery validation scripts.
• What is the difference between ASP.NET Web Forms and MVC?
  Web Forms use event-driven development with ViewState, while MVC uses a cleaner, RESTful pattern with full control over HTML.
• What is routing in MVC?
  Routing maps URLs to controller actions. It’s defined in RouteConfig.cs or via attribute routing in .NET Core.
• What are anonymous functions or lambda expressions in MVC?
  They simplify delegates and LINQ queries, commonly used in Razor views and controllers like: (x => x.Id == 5)
• What is Entity Framework (EF) and how is it used?
  EF is an ORM that connects C# classes to database tables. You can use Code First, Database First, or Model First approaches to map and manipulate data.
• What is Singleton in MVC? Is your application Singleton?
  Singleton is a design pattern ensuring a class has only one instance. In MVC, it can be used in service classes via Dependency Injection.
• What is Dependency Injection (DI)?
  DI is a design pattern where dependencies are injected rather than hardcoded. ASP.NET Core has built-in DI support, improving testability and maintainability.
• What are filters in MVC?
  Filters like Authorization, Action, Result, and Exception Filters help execute logic at different points in the request lifecycle. Useful for logging, caching, or security.

🛢️ SQL Server Interview Questions

• What is a JOIN? List its types and when to use each.
  JOINs combine rows from multiple tables:
  • INNER JOIN – Matching rows only
  • LEFT JOIN – All rows from left table
  • RIGHT JOIN – All rows from right table
  • FULL OUTER JOIN – All rows from both
• What is a correlated subquery?
  A subquery that refers to columns from the outer query. Executed for each row, often used for row-wise comparisons.
• What is a stored procedure and why is it important?
  A stored procedure is a precompiled group of SQL statements stored in the database. It improves performance, security, and reusability.
• Difference between SQL Server 2008 and newer versions?
  SQL Server 2022+ includes advanced features like AI integration, enhanced performance tuning, temporal tables, and graph DB support. 2008 lacks these modern features.
• How do you use Common Table Expressions (CTE)?
  CTEs simplify complex queries with temporary result sets. Syntax:
  WITH CTE AS (SELECT ... ) SELECT * FROM CTE WHERE ...;
• What is indexing and how does it impact performance?
  Indexing improves query speed. Use clustered indexes for primary keys and non-clustered indexes for frequently searched columns.
• What is normalization?
  It's a process to reduce data redundancy. 1NF, 2NF, 3NF ensure that data is stored efficiently and relationships are logically structured.

🔗 WCF (Windows Communication Foundation)

• How do you implement security in WCF?
  By configuring bindings (WSHttpBinding), using transport (SSL) or message-level security, and enabling authentication via username, Windows, or certificate.
• What is an Endpoint in WCF?
  Endpoint = ABC: Address, Binding, Contract. It defines how and where a WCF service communicates with clients.
• How do you consume a WCF service in your application?
  Add Service Reference → auto-generates client proxy. Or use ChannelFactory for advanced scenarios.
• What is the difference between Web Services and WCF?
  WCF supports multiple protocols (HTTP, TCP, MSMQ), multiple bindings, and has better security and performance options than traditional ASMX web services.
• How do you handle fault exceptions in WCF?
  By using FaultContract attributes to define structured error messages and handling them in the client with try/catch blocks.
• What are bindings in WCF?
  Bindings define how communication happens. Examples: BasicHttpBinding (interoperability), NetTcpBinding (performance), WSHttpBinding (security).

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📘 Bonus Tips for Interview Success:

• Always answer with real project examples
• Prepare a mini demo project (CRUD with MVC + EF + SQL)
• Know your resume inside-out—especially project architecture
• Practice SQL joins, stored procedures, and C# OOP concepts

💬 Pro Tip: Don’t just memorize answers—understand the “why” behind each concept. Interviewers look for real understanding, not textbook definitions.

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🚀 With the right prep, your .NET dream job is just one confident answer away. Keep practicing and stay sharp!

🧠 Additional Insights for .NET Interview Success in 2025

In addition to mastering technical questions, candidates should demonstrate their ability to architect maintainable systems and navigate real-world enterprise challenges. Below are extended insights across architecture, testing, deployment, and soft skills that interviewers increasingly prioritize.

🔧 Advanced MVC & .NET Core Concepts

In 2025, many organizations have migrated to .NET Core or .NET 8/9 for better cross-platform support and performance. Here are a few advanced topics you should be ready to discuss:

• Middleware Pipeline: Understand how middleware works in .NET Core to process HTTP requests, apply global error handling, and implement custom logic like token verification or logging.
• Custom Tag Helpers: In Razor views, Tag Helpers are powerful for creating reusable UI components.
• Action Filters: Use filters for cross-cutting concerns like authorization, logging, or input validation.
• Health Checks & Monitoring: Integrate with tools like Prometheus or Grafana to monitor system health.

🧪 Unit Testing, Mocks & TDD

Go beyond saying “yes, I write unit tests” — explain how:

• Use xUnit or NUnit for writing modular unit tests.
• Mock services using Moq to isolate dependencies.
• Follow the Arrange-Act-Assert (AAA) pattern.
• Leverage code coverage tools like Coverlet and CI tools like Azure DevOps for test pipelines.

🔄 CI/CD & DevOps Basics

Even for non-DevOps roles, .NET developers are expected to understand the basics of CI/CD workflows:

• CI: Use GitHub Actions or Azure Pipelines to run tests, analyzers, and scans after commits.
• CD: Automate staging/production deployments with rollback and config transforms.
• Handle environment variables and secrets using Azure Key Vault or similar.

📦 Containerization & Microservices

Exposure to Docker and container deployment gives you an edge:

• Create Dockerfiles for .NET APIs and deploy them in test/UAT environments.
• Use HTTP REST, gRPC, or message queues for microservice communication.

📊 SQL Server: Query Optimization Examples

SQL interviews often go deep, especially in data-heavy domains. Share real examples:

• Deadlock Resolution: How you fixed deadlocks in production.
• Query Execution Plans: How you tuned slow queries using execution plans.
• Discuss temporal tables or partitioning for big datasets.

🛡️ Security & Compliance

Show your ability to secure applications:

• Secure APIs using OAuth2 / JWT.
• Encrypt PHI/PII using SQL Server's Always Encrypted.
• Implement input sanitization, anti-CSRF tokens, and rate limiting.

🧠 Behavioral & Scenario-Based Thinking

Employers value mindset and soft skills. Prepare these:

• Use STAR method: Frame experiences with Situation → Task → Action → Result.
• Handle conflict: How do you deal with team disagreements on design?
• Production issues: Share how you debugged and rolled back a faulty release.

✅ Final Interview Readiness Checklist

• You understand request flow from MVC to DB and back.
• You’ve practiced SQL joins, indexes, and CTEs.
• You can debug slow endpoints using logs and profiling.
• You can write unit tests using xUnit and Moq.
• You can explain design patterns like Repository, Singleton, and Factory.
• You’ve practiced STAR-format answers for real project experiences.

With this extended prep, you now cover all the bases — core development, testing, database, design principles, and real-world application. Stay curious, communicate clearly, and back up your answers with real examples.

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