.Net Interview Questions Discussion
.NET Interview Questions Discussion | Complete Session Summary
In this session, we discussed important .NET interview topics frequently asked in real-world technical interviews, along with practical examples and strategies to answer confidently.
Boxing & Unboxing?
.NET REST Architecture?
Deferred Execution in LINQ?
Web API vs Rest Services vs Micro Services?
Rest principles?
Repository pattern?
POST vs PUT?
How to scale an API?
What is Race Condition?
SQL Transaction?
Atomic SQL Update?
Rabbit MQ?
📌 C# Concepts
Boxing & Unboxing
Understanding Value Types vs Reference Types
Stack Memory vs Heap Memory
Boxing: Converting a value type to an object
Unboxing: Converting an object back to a value type
Real-Time Example: ArrayList
ArrayList accepts multiple data types (int, string, object, etc.)
Internally performs boxing and unboxing operations
Causes additional memory and performance overhead
How Generics Solve the Problem
Use List[T] instead of ArrayList
Eliminates boxing/unboxing overhead
Provides compile-time type safety
Improves application performance
String vs StringBuilder
String creates a new memory allocation for every modification
StringBuilder reuses existing memory
Better performance for frequent string manipulations
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🌐 REST & API Architecture
REST Principles
Client-Server Independence
Stateless Communication
Cacheable Responses
Uniform Interface
Scalability & Security
Code on Demand
API Concepts
Difference between Web API, REST API, and Microservices
HTTP Action Verbs:
GET
POST
PUT
DELETE
API Gateway Responsibilities
Authentication & Authorization
Rate Limiting
Request Validation
Load Balancing
Routing Requests to Services
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🏗️ System Design & Distributed Systems
Race Condition Scenario
Example: Two users trying to purchase the last available product simultaneously.
Solutions Discussed
#### Database-Level Locking
SQL Transactions
Table/Row Locking
Trade-offs and performance impact
#### Redis Distributed Lock
Prevents concurrent updates
Reduces database locking overhead
Common approach in distributed systems
Messaging Queues
RabbitMQ
Azure Service Bus
AWS SQS
Use Cases:
Notifications
Email Processing
Background Jobs
Communication between Microservices
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🎯 Design Patterns & Architecture
Design Patterns Covered
Repository Pattern
CQRS (Command Query Responsibility Segregation)
Unit of Work
Singleton Pattern
Architecture Concepts
Clean Architecture
Domain-Driven Design (DDD)
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☁️ Azure & Deployment
Deployment Process Overview
GitHub Actions
Docker
Kubernetes
Jenkins
SonarQube
Visual Studio Modes
Debug Mode
Release Mode
Key differences and use cases
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🚀 Agile & Scrum
Velocity in Agile
Discussion on:
Team Availability
Story Points
Sprint Planning
Measuring Team Capacity
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💡 Interview Strategy & Tips
Recommended Answer Structure
1. Definition
2. Technical Explanation
3. Real-Time Example
4. Industry Use Case
5. Best Practice / Optimization
Example: Boxing & Unboxing
Common Answer:
"Boxing means converting int to object, and unboxing means converting object back to int."
Interview-Ready Answer:
"ArrayList accepts any data type and internally performs boxing and unboxing when storing value types. This creates additional memory and performance overhead because objects move between stack and heap memory. To overcome this issue, modern applications use generic collections like List[T], which provide type safety and eliminate boxing/unboxing operations."
Key Interview Tip
Many candidates stop at definitions. To stand out:
Explain the concept
Connect it to a real-world scenario
Discuss performance implications
Suggest an industry-standard solution
This approach helps deliver memorable, practical, and impactful interview answers.
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