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
Backend Engineer
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Behavioral
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medium
Tell me about a time you had a disagreement with a client regarding a technical requirement. How did you handle it?
#Communication
#Client Management
#Conflict Resolution
Backend Engineer
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Behavioral
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medium
Describe a situation where you had to deliver a critical backend feature under a very tight deadline.
#Time Management
#Delivery
#Agile
Backend Engineer
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Behavioral
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easy
How do you ensure code quality and maintainability within your development team?
#Best Practices
#Code Review
#CI/CD
Backend Engineer
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Behavioral
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medium
Tell me about a time you found a critical bug in production. How did you handle the incident?
#Incident Management
#Debugging
#Accountability
Backend Engineer
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Coding
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medium
Write a Java program to find the first non-repeating character in a string using Java 8 Streams.
#Java 8
#Streams
#Strings
Backend Engineer
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Coding
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easy
Write a SQL query to find the second highest salary of an employee from an Employee table.
#Database
#Queries
Backend Engineer
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Coding
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medium
Write a SQL query to find duplicate records in a table based on a specific column, and return the count of duplicates.
#Database
#Group By
#Having
Backend Engineer
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Coding
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medium
Implement a thread-safe Singleton class in Java.
#Multithreading
#Core Java
Backend Engineer
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Coding
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easy
Given an array of integers and a target sum, return the indices of the two numbers that add up to the target. (Two Sum)
#Arrays
#HashMaps
Backend Engineer
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Coding
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easy
Write a program to merge two sorted linked lists into a single sorted linked list.
#Linked Lists
#Pointers
Backend Engineer
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Coding
•
medium
Given an array of strings, group the anagrams together.
#Strings
#HashMaps
Backend Engineer
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Coding
•
easy
Write a function to reverse a string in-place without using built-in functions like `StringBuilder.reverse()`.
#Strings
#Two Pointers
Backend Engineer
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System Design
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hard
Explain the Saga design pattern. How would you implement it for distributed transactions across microservices?
#Distributed Systems
#Transactions
#Event Driven
Backend Engineer
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System Design
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hard
Design a microservices architecture for a banking fund transfer application. How do you ensure ACID properties across services?
#Microservices
#Banking
#ACID
Backend Engineer
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System Design
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hard
Design a highly available healthcare patient record API. How do you handle data privacy and compliance (like HIPAA)?
#Security
#High Availability
#Healthcare
Backend Engineer
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System Design
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medium
How do you implement distributed tracing in a microservices architecture?
#Observability
#Spring Cloud Sleuth
#Zipkin
Backend Engineer
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System Design
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hard
Design an API Rate Limiter. What algorithms would you use?
#Algorithms
#Scalability
#Caching
Backend Engineer
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System Design
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hard
Design the backend for an E-commerce inventory management system. How do you handle concurrent purchases of the same item?
#Concurrency
#Microservices
#Databases
Backend Engineer
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Technical
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medium
Explain the internal working of ConcurrentHashMap in Java. How does it achieve thread safety without locking the entire map?
#Collections
#Multithreading
#Concurrency
Backend Engineer
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Technical
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medium
How does Spring Boot auto-configuration work under the hood?
#Framework Internals
#Annotations
Backend Engineer
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Technical
•
medium
How do you handle exceptions globally in a Spring Boot REST API?
#REST
#Error Handling
Backend Engineer
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Technical
•
medium
What is the N+1 select problem in Hibernate/JPA, and how do you resolve it?
#Hibernate
#JPA
#Performance Tuning
Backend Engineer
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Technical
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medium
How do you secure a REST API? Explain the JWT authentication flow.
#Authentication
#REST
#JWT
Backend Engineer
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Technical
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medium
Explain the role of an API Gateway in a microservices ecosystem. What cross-cutting concerns does it handle?
#Architecture
#Routing
#Security
Backend Engineer
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Technical
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hard
How do you handle message consumption failures in Kafka to ensure no data is lost?
#Kafka
#Resiliency
#DLQ
Backend Engineer
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Technical
•
medium
What is the difference between Clustered and Non-Clustered Indexes in a relational database?
#Database
#Indexing
#Performance
Backend Engineer
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Technical
•
medium
How do you approach optimizing a slow-running query in PostgreSQL or Oracle?
#Performance Tuning
#Execution Plan
Backend Engineer
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Technical
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easy
How do you implement pagination and sorting in Spring Data JPA?
#JPA
#API Design
Backend Engineer
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Technical
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hard
Explain how Garbage Collection works in Java 11/17, specifically focusing on G1GC.
#JVM
#Memory Management
Backend Engineer
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Technical
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hard
What is the difference between `@Transactional(propagation = Propagation.REQUIRED)` and `REQUIRES_NEW`?
#Transactions
#Database
Backend Engineer
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Technical
•
medium
How do you resolve Circular Dependencies in a Spring Boot application?
#Dependency Injection
#Architecture
Backend Engineer
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Technical
•
medium
Explain the Bean lifecycle in the Spring framework.
#Framework
#IoC
Backend Engineer
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Technical
•
medium
What are the key differences between REST and GraphQL? When would you choose GraphQL over REST?
#Web Services
#Architecture
Backend Engineer
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Technical
•
medium
Explain the CAP theorem. How does it influence your choice of database for a microservice?
#Databases
#Architecture
Backend Engineer
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Technical
•
easy
What is the difference between `@Component`, `@Service`, and `@Repository` in Spring?
#Annotations
#Architecture
Difficulty Radar
Based on recent AI-sourced data.
Meet Your Interviewers
The "Standard" Interviewer
Senior EngineerFocuses on core competencies, system constraints, and clear communication.
SimulateUnwritten Rules
Think Out Loud
Always explain your thought process before writing code or drawing architecture.