Cognizant Software Engineer Interview Questions and Answers for Experienced

OOPS concepts are fundamental to software engineering, with examples like inheritance, encapsulation, and polymorphism.

• Inheritance: A child class inherits properties and behaviors from a parent class. For example, a Car class can inherit from a Vehicle class.

• Encapsulation: Bundling data and methods that operate on the data into a single unit. For example, a BankAccount class with private variables and public metho...read more

Multithreading is the ability of a CPU to execute multiple threads concurrently, allowing for better performance and responsiveness in software applications.

• Multithreading allows multiple threads to run concurrently within the same process.

• Each thread has its own stack and program counter, but shares the same memory space.

• Multithreading can improve performance by utilizing multiple CPU cores efficiently.

• Examples o...read more

Monolithic architecture is a single-tiered software application where all components are interconnected and interdependent, while Microservices is a distributed architecture where the application is broken down into smaller, independent services.

• Monolithic architecture is a single, indivisible unit, making it difficult to scale and update without affecting the entire system.

• Microservices architecture breaks down t...read more

Java Spring is a powerful framework for building enterprise-level applications with ease and flexibility.

• Dependency Injection: Simplifies code management by allowing developers to inject dependencies rather than hard-coding them.

• Aspect-Oriented Programming: Enables separation of cross-cutting concerns, such as logging and security, improving code modularity.

• Spring Boot: A sub-project that simplifies the setup and ...read more

String is immutable while StringBuffer is mutable in Java.

• StringBuffer is more efficient when performing a lot of string manipulations

• StringBuffer has methods to append, insert, and delete characters

• String is better for small string operations and is thread-safe

• StringBuffer is not thread-safe but can be made thread-safe with synchronization

• Example: String str = "hello"; StringBuffer sb = new StringBuffer(str);

• Exam...read more

Interface defines only method signatures while abstract class can have both method signatures and implementations.

• An interface can be implemented by multiple classes while an abstract class can only be extended by one class.

• An abstract class can have constructors while an interface cannot.

• An abstract class can have instance variables while an interface cannot.

• An abstract class can have non-abstract methods while a...read more