Cognizant (CTS) Interview Experience – 2025 (IT Branch)
Summary
I recently interviewed with Cognizant for an IT role, which was a comprehensive experience involving technical discussions on OOPs, Java, C++, and APIs, alongside solving two on-the-spot coding problems. The interview also covered standard HR questions regarding my adaptability and willingness to relocate, lasting about an hour.
Full Experience
I recently underwent an interview process for an IT role at Cognizant. My preparation included an 8-week structured training program that delved into Data Structures and Algorithms (DSA), Object-Oriented Programming (OOPs), Database Management Systems (DBMS), Operating Systems (OS), Java, and general problem-solving. This training was followed by a final assessment.
The interview itself took place at KL University. I reported at 8:00 AM and finally received my interview call at 4:00 PM, with the session lasting approximately one hour. The panel comprised two interviewers, one conducting virtually and the other in-person.
The interview began with my self-introduction, after which the panel transitioned into core technical areas. We discussed topics such as the differences between Method Overloading and Overriding, Exception Handling in Java, the distinction between Checked and Unchecked exceptions, what a Null Pointer Exception is and how to handle it, and the different usages of 'final', 'finally', and 'finalize'. We also covered the FIFO principle, basics of Multithreading, the internal implementation of HashMap, and the differences between List and Set data structures. My language preference (C++ vs. Java) was explored, along with questions about data types in C++ and the memory size of 'int' in both C++ and Java. Finally, API concepts, including what an API is and its usage, and specifically what a REST API is, were also part of the technical discussion.
For the coding section, I was given two problems to solve on the spot: "Reverse a String" and "Merge Two Maps".
The HR round focused on behavioral aspects, asking about my hometown, my willingness to relocate, comfort with working in shifts, and my adaptability to learning new programming languages in the future.
Overall, I found the interview panel to be friendly. They thoroughly assessed my technical depth across OOPs, Java, C++ concepts, APIs, collections, and multithreading, along with my basic but sometimes tricky coding ability. The HR questions primarily checked for flexibility and adaptability. It was a valuable learning experience that tested my conceptual clarity, problem-solving skills, and communication, all within an hour.
Interview Questions (20)
Method Overloading vs. Overriding
Explain the differences between method overloading and method overriding in object-oriented programming.
Exception Handling in Java
Describe the principles and mechanisms of exception handling in Java.
Checked vs. Unchecked Exceptions
Explain the difference between checked and unchecked exceptions in Java and provide examples.
Null Pointer Exception Handling
What is a Null Pointer Exception (NPE) and what are common strategies to prevent and handle it in Java?
final, finally, finalize Keywords
Explain the purpose and usage of the keywords 'final', 'finally', and 'finalize' in Java.
FIFO Principle Explanation
Explain the First-In, First-Out (FIFO) principle and provide examples of its application.
Basics of Multithreading
Describe the fundamental concepts of multithreading and its benefits/challenges.
HashMap Internal Implementation
Explain what a HashMap is and describe its internal working and implementation details in Java.
Set vs. List Data Structures
Define what a Set is and explain the key differences between List and Set data structures.
C++ vs. Java Preference
Discuss the pros and cons of C++ and Java, and justify a preference for C++.
Data Types in C++
List and explain common data types available in C++.
Memory Size of int (C++ vs. Java)
Compare the typical memory size of an 'int' data type in C++ and Java.
API Definition and Usage
Define what an Application Programming Interface (API) is and describe its common usage.
REST API Explained
Explain what a REST API is, including its principles and characteristics.
Reverse a String
Write code to reverse a given string.
Merge Two Maps
Given two maps, write code to merge them into a single map. Handle potential key conflicts.
Background about Hometown
Tell me about the city you belong to and provide details about it.
Willingness to Relocate
Are you willing to relocate for this role?
Comfort with Shifts
Are you comfortable working in different shifts?
Adaptability to New Technologies
If new programming languages emerge in the future, will you be able to learn them and adapt?
Preparation Tips
My preparation involved an 8-week structured training program covering DSA, OOPs, DBMS, OS, Java, and general problem-solving. For those preparing, I recommend thoroughly revising OOPs, Exception Handling, Collections, APIs, and DSA basics. It's crucial to be confident in your chosen programming language (C++ or Java) and to practice simple coding problems, particularly those involving string manipulation and map operations.