Cognizant
American multinational information technology services and consulting company.
4 Rounds
~21 Days
Medium
The Interview Loop
Recruiter Screen (30 min)
Standard fit check, behavioral questions, and resume overview.
Technical Loop (3-4 Rounds)
Deep dive into domain knowledge, coding, and system design.
Interview Question Bank
Data Engineer
•
Coding
•
easy
Given a list of dictionaries representing employee data, write a Python script using list comprehensions to extract the names of employees who belong to the 'IT' department and have a salary > 80000.
#List Comprehensions
#Data Manipulation
Data Engineer
•
Coding
•
medium
Write a Python generator function that reads a massive log file line by line and yields lines containing the word 'ERROR'. Why use a generator here?
#Generators
#Memory Management
#File I/O
Data Engineer
•
Coding
•
hard
Write a Python script to flatten a deeply nested JSON object representing a client's API response into a flat dictionary.
#Recursion
#JSON
#Data Parsing
Data Scientist
•
Coding
•
medium
Write a Python function using Pandas to merge two large datasets (10M+ rows) efficiently. What potential memory issues might you face and how do you resolve them?
#Pandas
#Memory Management
#Data Merging
Data Scientist
•
Coding
•
easy
Write a Python script from scratch to detect anomalies in a list of daily transaction volumes using the Z-score method.
#Statistics
#Anomaly Detection
#Arrays
Data Scientist
•
Coding
•
hard
Implement a basic TF-IDF vectorizer function in Python without using scikit-learn. It should take a list of strings and return a dictionary of TF-IDF scores.
#NLP
#Text Processing
#Math
Difficulty Radar
Based on recent AI-sourced data.
Meet Your Interviewers
The "Standard" Interviewer
Senior EngineerFocuses on core competencies, system constraints, and clear communication.
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Think Out Loud
Always explain your thought process before writing code or drawing architecture.