I had two interviewers for my Cognizant interview—one was present in-person (offline), and the other joined online. Both interviewers introduced themselves before proceeding with their respective questions.
Offline Interview: Python
General Questions:
- Introduce yourself.
- Rate yourself in Python, SQL, and Cloud Computing on a scale of 1-5.
Python Concepts:
- Explain Python’s built-in data structures.
- What is the difference between a list and a tuple?
- Define list comprehension.
- What is a lambda function?
- Explain polymorphism in Python.
- Differentiate between method overriding and method overloading.
Coding Questions:
- Print only the unique values (no duplicates) from a list of strings.
- Create a dictionary showing the count of each string from the same list.
Note: A compiler was provided for coding tasks.
Online Interview: SQL
Basic SQL Concepts:
- What is a database?
- Differentiate between a table and a view.
- Can data be added to a view?
- What are the different constraints in SQL?
- Define primary and foreign keys.
Queries and Clauses:
- Explain the WHERE and GROUP BY clauses.
- Write a query to find the number of students from India enrolled in foreign universities.
- Modify the query to display the count only if the number exceeds 5.
Scaling:
- Explain horizontal scaling and vertical scaling.
Note: A compiler was provided for SQL queries.
Offline Interview: Cloud Computing
Core Concepts:
- What is virtualization?
- Types of virtualization.
- Explain containers in server virtualization.
- Define cloud computing and its benefits.
Cloud Models:
- Differentiate between scale-up and scale-out.
- Explain IaaS, PaaS, and SaaS.
- Provide examples for each cloud computing model.
Resume-Based Questions
Machine Learning Project:
- Explain your machine learning project in detail.
- What is ANN (Artificial Neural Network)?
- Which type of ANN was used in your project?
- Details about input data, input neurons, and output layers.
Internship:
- Briefly describe your internship tasks.
Note: No follow-up questions were asked about the internship.
Final Question
The interview concluded with the interviewer asking if I had any questions. The entire session lasted approximately 1 hour.
This experience gave me valuable insights into the expectations at Cognizant and covered diverse technical and project-related topics.