60+ Dot Net Fullstack Developer Interview Questions and Answers

The .NET framework supports multiple languages including C#, VB.NET, F#, and C++.

• C# is the most commonly used language for .NET development

• VB.NET is a popular choice for legacy applications

• F# is used for functional programming

• C++ is used for performance-critical applications

• Other languages like IronPython and IronRuby can also be used with .NET

Catching in .NET is a mechanism to handle exceptions that occur during program execution.

• Catching is done using try-catch blocks.

• Types of catching include specific exception catching, general exception catching, and re-throwing exceptions.

• Specific exception catching is done using catch blocks that specify the type of exception to catch.

• General exception catching is done using catch blocks that catch all exceptions.

• Re-throwing exceptions is done using the throw keyword within ...read more

OOPs concepts like inheritance, encapsulation, polymorphism, and abstraction were used in my previous projects for designing modular and reusable code.

• Inheritance: Used to create parent-child relationships between classes. For example, a base class 'Vehicle' with child classes 'Car' and 'Truck'.

• Encapsulation: Used to hide the internal implementation details of a class and only expose necessary methods and properties. For example, private variables and public methods in a 'Use...read more

Interview process includes direct face-to-face interaction with panel and coding evaluation.

• Expect to have a video call with the interview panel

• Be prepared to showcase your coding skills during the call

• Ensure you have a stable internet connection and a quiet environment for the call

• Practice coding problems beforehand to feel more confident

• Be ready to explain your thought process and approach to problem-solving

OOPs is a programming paradigm that uses objects to represent real-world entities. .NET framework supports OOPs concepts.

• OOPs stands for Object-Oriented Programming.

• .NET framework supports OOPs concepts like encapsulation, inheritance, and polymorphism.

• In OOPs, objects are created from classes, which act as blueprints for the objects.

• Example: In .NET, a class can be created to represent a customer with properties like name, address, and methods like placeOrder().

• OOPs helps in...read more

Use the OFFSET and FETCH clauses in SQL to get the 5th top position data.

• Use the ORDER BY clause to sort the data in descending order.

• Use the OFFSET clause to skip the first 4 rows.

• Use the FETCH clause to retrieve only the next row after skipping the first 4 rows.

Create a simple model view controller to retrieve values from a database

• Create a model class to represent the data structure from the database

• Create a controller to handle requests and interact with the model

• Create a view to display the data retrieved from the database

Resolvers in Angular are used to fetch data before the component is loaded, canActivate guards control access to routes, custom decorators can be created using @Decorator syntax, ngOnInit is a lifecycle hook in Angular, asynchronous methods can be made synchronous using async/await, cancellation tokens are used to cancel asynchronous operations.

• Resolvers in Angular are used to fetch data before the component is loaded, ensuring that the component has the necessary data when i...read more

Authentication verifies the identity of a user, while authorization determines what resources a user can access.

• Authentication confirms the identity of a user through credentials like username and password.

• Authorization determines the permissions and access levels of a user based on their authenticated identity.

• In ASP.NET Core, authentication is handled through middleware like Identity, OAuth, or JWT tokens.

• Authorization in ASP.NET Core is managed through policies and roles d...read more

Use a query to print a word from horizontal to vertical

• Use the TRANSLATE function in SQL to convert each character of the word into a separate row

• Use a recursive CTE (Common Table Expression) to achieve the desired output

• Consider using a loop in a programming language to iterate over each character of the word and print vertically

Polymorphism is the ability of a single function or method to operate on different data types. Interface is a contract that defines the methods that a class must implement. Multithreading is the ability of a CPU to execute multiple threads concurrently. C# does not support multiple inheritance. Inheritance is a mechanism in OOP where a class inherits properties and behaviors from another class. Methods are functions defined within a class. void main() is the entry point of a ...read more

Session management in ASP.NET Core involves storing and retrieving user-specific data during a user's visit to a website.

• Session data is stored on the server side by default in ASP.NET Core

• Session data can be accessed and manipulated using the HttpContext.Session property

• Session data can be configured to use different storage providers such as in-memory, distributed cache, or SQL Server

• Session data is typically used to store user-specific information like user ID, shopping ca...read more

SQL queries for creating database tables using DML and DDL

• Use CREATE TABLE statement for DDL to create a new table

• Use INSERT INTO statement for DML to insert data into the table

• Use SELECT statement to retrieve data from the table

• Use UPDATE statement to modify existing data in the table

• Use DELETE statement to remove data from the table

Authentication is the process of verifying the identity of a user, while authorization is the process of determining what resources a user can access.

• Authentication can be done using various methods such as username/password, tokens, or biometrics.

• Authorization involves assigning roles or permissions to users based on their identity.

• Authentication and authorization are often implemented using frameworks like OAuth or JWT.

• Examples include logging in with a username and passwor...read more

Model binding is the process of mapping data from HTTP requests to objects in MVC and ASP.NET Core.

• Model binding automatically maps data from HTTP requests to action method parameters or properties of a model class.

• It simplifies the process of retrieving data from forms, query strings, route values, and JSON/XML payloads.

• Model binding can be customized using attributes like [Bind], [FromQuery], [FromBody], etc.

• Example: In ASP.NET Core, a POST request with form data can be aut...read more

Implementing API for CRUD operations involves creating endpoints for Create, Read, Update, and Delete operations.

• Create endpoints for each CRUD operation (POST for Create, GET for Read, PUT for Update, DELETE for Delete)

• Use appropriate HTTP methods and status codes (e.g. 200 for successful operation, 404 for not found)

• Implement validation for input data to ensure data integrity

• Secure the API endpoints to prevent unauthorized access

• Test the API using tools like Postman to ensu...read more

Functional components are simpler, stateless, and use functional programming concepts. Class components are more complex, stateful, and use ES6 class syntax.

• Functional components are just plain JavaScript functions that accept props as arguments and return React elements.

• Class components are ES6 classes that extend from React.Component and can have state and lifecycle methods.

• Functional components are easier to read, write, and test.

• Class components have access to lifecycle m...read more

Print 'hello world!!' in three separate lines.

• Use a programming language's print function to output 'hello' on the first line, 'world' on the second line, and '!!' on the third line.

• In JavaScript, you can achieve this using console.log() function with line breaks like console.log('hello\nworld\n!!');

Microservices offer benefits such as scalability, flexibility, and easier maintenance.

• Scalability: Microservices allow for individual components to be scaled independently, leading to better resource utilization.

• Flexibility: Each microservice can be developed, deployed, and updated independently, allowing for more flexibility in the development process.

• Easier maintenance: With microservices, it is easier to identify and fix issues as each service is isolated and has its own c...read more

Generate all possible combinations of a suite of cards

• Create an array of all possible card values (e.g. '2', '3', '4', '5', '6', '7', '8', '9', '10', 'J', 'Q', 'K', 'A')

• Create an array of all possible card suits (e.g. 'Hearts', 'Diamonds', 'Clubs', 'Spades')

• Iterate through the card values and suits to generate all combinations (e.g. '2 of Hearts', '3 of Hearts', '4 of Hearts', ...)

Project flow involves planning, development, testing, deployment, and maintenance.

• 1. Requirement gathering and analysis

• 2. Designing the architecture and database

• 3. Development of front-end and back-end components

• 4. Testing and debugging

• 5. Deployment and release

• 6. Maintenance and updates

ViewBag and ViewData are used in ASP.NET MVC to pass data from controller to view.

• ViewBag is a dynamic property that allows you to pass data from controller to view.

• ViewData is a dictionary object that allows you to pass data from controller to view.

• ViewBag is a dynamic object while ViewData is a dictionary object.

• Example: ViewBag.Title = 'Home Page'; ViewData['Message'] = 'Welcome to my website';

Frontend can connect to backend through API calls, web sockets, or GraphQL queries.

• Use API calls to send requests from frontend to backend and receive responses

• Implement web sockets for real-time communication between frontend and backend

• Utilize GraphQL queries to fetch specific data from backend as needed

My strengths include problem-solving, adaptability, and teamwork.

• I am skilled in identifying and resolving complex technical issues.

• I am able to quickly adapt to new technologies and work environments.

• I am a team player and enjoy collaborating with others to achieve common goals.

Use SQL query with ORDER BY and LIMIT to find 3rd highest salary

• Use ORDER BY clause to sort salaries in descending order

• Use LIMIT 2,1 to skip first two highest salaries and get the third highest salary

Inheritance is an 'is-a' relationship where a class inherits properties and behaviors from another class. Composition is a 'has-a' relationship where a class contains an instance of another class.

• Inheritance involves creating a new class by using existing class's properties and behaviors.

• Composition involves creating a class that contains an instance of another class.

• Inheritance promotes code reusability and is used for 'is-a' relationships like a car is a vehicle.

• Composition...read more

Handling stressful scenarios involves staying calm, prioritizing tasks, seeking support, and practicing self-care.

• Stay calm and take deep breaths to manage emotions

• Prioritize tasks based on urgency and importance

• Seek support from colleagues, mentors, or counselors

• Practice self-care activities like exercise, meditation, or hobbies

Normalization is the process of organizing data in a database to eliminate redundancy and improve data integrity.

• Normalization helps in reducing data redundancy by breaking down a large table into smaller, more manageable tables.

• It ensures that each piece of data is stored in only one place, reducing the chances of inconsistencies.

• Normalization follows a set of rules called normal forms, such as First Normal Form (1NF), Second Normal Form (2NF), etc.

• Each normal form has speci...read more

Dependency injection is a design pattern used to remove hard-coded dependencies and make code more flexible and testable.

• It allows objects to be created with their dependencies rather than having to create them within the object itself.

• It promotes loose coupling between objects.

• It makes code more modular and easier to maintain.

• Examples include using a DI container like Unity or Autofac, or manually injecting dependencies through constructors or properties.

LSP is a principle of SOLID design that states that objects of a superclass should be replaceable with objects of its subclasses.

• LSP stands for Liskov Substitution Principle

• It ensures that the behavior of the program remains consistent when a subclass is used in place of its superclass

• Violating LSP can lead to unexpected behavior and bugs

• Example: If a program expects a Bird object, it should be able to use any subclass of Bird (e.g. Eagle, Penguin) without issues

SQL is a programming language used to manage and manipulate relational databases. Queries are commands used to retrieve data from databases.

• SQL stands for Structured Query Language

• Queries are used to retrieve specific data from a database

• SQL can be used to create, modify, and delete databases and tables

• Examples of SQL commands include SELECT, INSERT, UPDATE, and DELETE

String is a sequence of characters, while StringBuilder is a mutable sequence of characters used for efficient string manipulation.

• String is immutable, meaning once created, it cannot be changed. Any operation that appears to modify a string actually creates a new string object.

• StringBuilder is mutable, allowing for efficient manipulation of strings without creating new objects each time.

• Example: String str = "Hello"; StringBuilder sb = new StringBuilder("Hello"); sb.append("...read more

Solid Principles are a set of five design principles for writing clean, maintainable, and scalable code.

• Single Responsibility Principle: A class should have only one reason to change.

• Open/Closed Principle: Classes should be open for extension but closed for modification.

• Liskov Substitution Principle: Objects of a superclass should be replaceable with objects of its subclasses without affecting the program's correctness.

• Interface Segregation Principle: Clients should not be fo...read more

My expected CTC is based on my experience, skills, and the market rate for Dot Net Fullstack Developers.

• Consider my years of experience in Dot Net development

• Factor in my expertise in fullstack development technologies like Angular and React

• Research the current market rate for Dot Net Fullstack Developers in the location of the job

• Provide a range rather than a specific number to allow for negotiation

Yield keyword is used in C# to return a sequence of values one at a time.

• Yield keyword is used in iterator methods to return each element one by one.

• It allows the method to return multiple values without needing to store them all in memory.

• Yield return statement is used to return a value from the iterator method.

Redux is a predictable state container for JavaScript apps. It helps manage the state of an application in a single immutable state tree.

• Redux consists of three main components: store, actions, and reducers.

• Store: holds the state of the application.

• Actions: describe what happened in the application.

• Reducers: specify how the state changes in response to actions.

• Example: store.dispatch(action) is used to dispatch an action to the store.

Stored procedures are precompiled SQL statements that can be stored and executed on a database server.

• Stored procedures improve performance by reducing network traffic and optimizing query execution.

• They can be used to enforce business rules and security measures.

• They can also be used to encapsulate complex logic and make it easier to maintain.

• Examples include procedures for inserting, updating, and deleting data, as well as procedures for generating reports and performing ca...read more

Promises are used for a single async operation while observables handle multiple async operations and can be cancelled.

• Promises are eager, meaning they start immediately upon creation.

• Observables are lazy, meaning they only start when subscribed to.

• Promises can only handle a single value or error, while observables can handle multiple values over time.

• Observables can be cancelled, while promises cannot be cancelled.

• Promises are not cancellable, while observables can be unsubs...read more

Object-Oriented Programming (OOP) is a programming paradigm based on the concept of objects, which can contain data in the form of fields and code in the form of procedures.

• OOP focuses on creating objects that interact with each other to solve a problem.

• Key principles of OOP include encapsulation, inheritance, and polymorphism.

• Encapsulation involves bundling data and methods that operate on the data into a single unit.

• Inheritance allows a class to inherit properties and behav...read more

CORS stands for Cross-Origin Resource Sharing, a security feature that allows servers to specify who can access their resources.

• CORS is a security feature implemented by browsers to prevent unauthorized access to resources on a different origin.

• It allows servers to specify which origins are allowed to access their resources through HTTP headers.

• CORS is commonly used to enable cross-origin requests in web applications, such as AJAX requests from a different domain.

• Without CORS...read more

.Net Core is a free, open-source, cross-platform framework for building modern, cloud-based, internet-connected applications.

• Developed by Microsoft as the successor to the .NET Framework

• Supports multiple operating systems like Windows, macOS, and Linux

• Provides high performance and scalability for web applications

• Includes a modular and lightweight runtime called CoreCLR

• Allows developers to use C#, F#, and Visual Basic for development

String is immutable in order to ensure data integrity and security.

• Immutable strings prevent accidental changes to data, ensuring consistency.

• Immutable strings allow for safe sharing of data between different parts of a program.

• Immutable strings help in multithreading scenarios where data should not be modified concurrently.

• Example: String str = "Hello"; str.concat(" World"); // This does not modify the original string, but creates a new one

Azure service is a cloud computing platform by Microsoft that provides various services for building, deploying, and managing applications.

• Azure service offers a wide range of services including virtual machines, storage, databases, and analytics.

• It also provides services for AI and machine learning, IoT, and DevOps.

• Azure service can be used for building and deploying web applications, mobile apps, and enterprise solutions.

• Some popular Azure services include Azure Virtual Mac...read more

Design patterns in .NET Core are reusable solutions to common problems in software design.

• Some common design patterns in .NET Core include Singleton, Factory, Observer, and Strategy.

• Design patterns help in creating maintainable, scalable, and efficient code.

• They promote code reusability and separation of concerns.

• Examples: Singleton pattern ensures a class has only one instance, Factory pattern creates objects without specifying the exact class, Observer pattern defines a one...read more

Interfaces in real world help in achieving abstraction and decoupling, allowing for flexibility and scalability in software development.

• Interfaces allow for multiple implementations of a common set of methods, promoting code reusability.

• Interfaces help in achieving loose coupling between different components of a system, making it easier to maintain and extend.

• Interfaces enable polymorphism, where objects can be treated as instances of their interface type, allowing for flexi...read more

A tuple is a data structure that stores a fixed number of elements of different data types.

• Tuples are immutable, meaning their values cannot be changed once they are set.

• They are commonly used to return multiple values from a function.

• Example: (1, 'apple', True) is a tuple with an integer, string, and boolean value.

Middleware is software that acts as a bridge between an application's front end and back end, allowing them to communicate and interact.

• Middleware can handle tasks such as authentication, logging, error handling, and routing.

• It can be used to modify incoming requests or outgoing responses.

• Examples of middleware include Express.js middleware in Node.js applications and ASP.NET middleware in .NET applications.