Hexaware Technologies Technical Lead Interview Questions and Answers

An immutable class is one whose instances cannot be modified after creation, ensuring thread safety and predictable behavior.

• Use 'final' keyword for class declaration: 'public final class ImmutableClass { }'

• Declare all fields as 'private final' to prevent modification: 'private final int value;'

• Provide a constructor to initialize all fields: 'public ImmutableClass(int value) { this.value = value; }'

• Avoid setter methods...read more

OOPs concept in .NET refers to Object-Oriented Programming principles like inheritance, encapsulation, polymorphism, and abstraction.

• Inheritance: Allows a class to inherit properties and behavior from another class.

• Encapsulation: Bundling data and methods that operate on the data into a single unit.

• Polymorphism: Ability to present the same interface for different data types.

• Abstraction: Hiding the complex implementatio...read more

Interface defines a contract for a class to implement, while abstraction hides the implementation details.

• Interface is a blueprint of a class that defines what methods a class must implement.

• Abstraction is a concept that hides the implementation details and shows only the functionality.

• Interfaces can have multiple inheritance, while abstraction can be achieved using abstract classes.

• Example: Interface 'Shape' may have ...read more

Middle tier is the layer of software that acts as a bridge between the front-end user interface and the back-end database.

• Middle tier handles business logic and processing of data

• It often includes application servers, web servers, and APIs

• Examples include Java EE, .NET Framework, and Node.js

SOLID principles are a set of five design principles that help make software designs more understandable, flexible, and maintainable.

• Single Responsibility Principle (SRP) - A class should have only one reason to change.

• Open/Closed Principle (OCP) - Software entities should be open for extension but closed for modification.

• Liskov Substitution Principle (LSP) - Objects of a superclass should be replaceable with objects o...read more

Session in .NET Core is used to store user-specific information across multiple requests.

• Use services.AddSession() in ConfigureServices method of Startup class to enable session

• Use app.UseSession() in Configure method of Startup class to add session middleware

• Access session data using HttpContext.Session property

• Example: HttpContext.Session.SetString("UserName", "JohnDoe") to store a string in session

• Example: string us...read more

ACID properties in DB ensure data integrity and consistency

• Atomicity: All operations in a transaction are completed successfully or none at all

• Consistency: Data is always in a valid state before and after a transaction

• Isolation: Transactions are isolated from each other until they are completed

• Durability: Once a transaction is committed, changes are permanent and survive system failures

Isolation levels define the level of visibility a transaction has on other concurrent transactions.

• Isolation levels include READ UNCOMMITTED, READ COMMITTED, REPEATABLE READ, and SERIALIZABLE.

• READ UNCOMMITTED allows dirty reads, READ COMMITTED prevents dirty reads but allows non-repeatable reads, REPEATABLE READ prevents non-repeatable reads but allows phantom reads, and SERIALIZABLE prevents all anomalies.

• Isolation le...read more