Cognizant, headquartered in New Jersey, hires a large number of freshers in India through its GenC programmes, such as GenC, GenC Next and GenC Pro, each with a different assessment level. The process usually includes an online assessment followed by technical and HR interviews. These Cognizant interview questions cover Java, SQL and web basics, situational questions and the HR round, with model answers.
20 questions · Updated
Programming, OOP, DBMS, operating systems and your project, the core of most Cognizant fresher interviews.
ArrayList is backed by a resizable array, so getting an element by index is O(1), but inserting or removing in the middle is O(n) because elements shift.
LinkedList is a doubly linked list, so adding or removing at the ends or at a known node is O(1), but accessing by index is O(n).
ArrayList is the better default because it uses less memory and is faster for most workloads.
A HashMap stores entries in an array of buckets.
The key's hashCode() decides the bucket; entries in the same bucket are stored in a linked list, which Java 8 converts to a balanced tree when a bucket grows large, so a lookup is O(1) on average. equals() finds the exact key within a bucket.
When the number of entries passes the load factor (0.75 by default), the array doubles and entries are rehashed.
It allows one null key and is not thread-safe; ConcurrentHashMap is.
Once a String is created, its value cannot change; methods like concat() return a new string.
This makes strings safe to share between threads and to use as HashMap keys (their hash code never changes), allows the JVM to reuse literals from the string pool to save memory, and improves security because values such as file paths cannot be changed after checks.
Use StringBuilder when building strings in a loop.
The JVM (Java Virtual Machine) runs compiled bytecode and handles memory management and garbage collection; it is what makes Java platform-independent.
The JRE (Java Runtime Environment) contains the JVM plus the core libraries needed to run Java programs.
The JDK (Java Development Kit) contains the JRE plus development tools such as the compiler (javac) and debugger, needed to write Java programs.
Both combine the results of two SELECT queries with the same number and types of columns.
UNION removes duplicate rows, which requires extra sorting or hashing work.
UNION ALL keeps all rows, including duplicates, so it is faster.
Use UNION ALL when you know there are no duplicates or want to keep them.
A join combines columns from multiple tables into one result based on a related column.
A subquery is a query nested inside another, used to filter or compute values, such as finding employees whose salary is above the average.
Many subqueries can be rewritten as joins, which are often faster because the optimiser handles them better, but subqueries can be easier to read.
An Armstrong number equals the sum of its digits each raised to the power of the number of digits, such as 153 = 1³ + 5³ + 3³. Count the digits, then add each digit raised to that power and compare with the original.
def is_armstrong(n):
digits = str(n)
power = len(digits)
return n == sum(int(d) ** power for d in digits)
# is_armstrong(153) -> True, is_armstrong(123) -> FalseTwo strings are anagrams if they contain the same characters with the same counts.
Compare character counts with a hash map or Counter, which is O(n), or compare the sorted strings, which is O(n log n).
Clarify whether case and spaces should be ignored.
from collections import Counter
def is_anagram(a, b):
return Counter(a.replace(" ", "").lower()) == Counter(b.replace(" ", "").lower())
# is_anagram("Listen", "Silent") -> Truevar is function-scoped, can be redeclared and is hoisted with the value undefined, which can cause bugs. let is block-scoped and can be reassigned but not redeclared in the same scope. const is block-scoped and cannot be reassigned, although the contents of a const object or array can still change. Modern code uses const by default and let when a value must change.
Responsive design makes a website adapt to any screen size.
It uses a viewport meta tag, flexible layouts with CSS Flexbox and Grid, relative units such as percentages and rem, responsive images, and media queries to change styles at different screen widths.
A mobile-first approach designs for small screens first, then adds styles for larger screens.
Situations at work, attitude and flexibility. Sometimes combined with the technical or HR round.
I would first spend a reasonable amount of time on it myself: read the error and logs, search documentation and forums, and try to isolate the problem.
If I am still stuck, I would ask a senior with a clear summary of what I tried, so their time is used well.
Asking too late wastes time, and asking too early stops you from learning.
I would accept it professionally, plan the move quickly and ask HR about any relocation support. I understand that business needs change and that working in a new place is a good learning experience.
I would stay calm and avoid confronting them publicly.
I would talk to them privately first, as it may be a misunderstanding, and in future make my contributions visible through regular updates to the lead and clear commit history.
If it continued, I would raise it with my manager with facts.
I follow coding standards, write meaningful names and small functions, write unit tests for my code, test edge cases, and review my own changes before raising a pull request. I also welcome code review feedback and use tools such as linters and static analysis.
Use the STAR method.
For example: "Two days before our project submission, our database crashed and we lost a week of test data.
I wrote a script to regenerate it from our logs, while my teammates continued the report, and we submitted on time."
Questions about Cognizant, its hiring programmes, relocation, shifts and your plans.
Be specific: "Cognizant works with clients in banking, healthcare, retail and technology, and its GenC programme gives freshers structured training and clear career paths. It is also investing in AI, cloud and digital engineering, which are areas I want to build skills in."
Cognizant Technology Solutions is an American IT services and consulting company headquartered in Teaneck, New Jersey.
It started in 1994 as a technology unit of Dun & Bradstreet with a large development centre in Chennai, became independent and grew into one of the largest IT services companies, with most of its workforce in India.
It serves industries such as banking, insurance, healthcare and life sciences.
They are Cognizant's fresher hiring profiles.
GenC is the main entry-level profile.
GenC Next and higher profiles such as GenC Pro or GenC Elevate are for candidates who perform strongly in harder coding assessments, with more advanced roles and higher packages.
Profiles and names change between drives, so check the current details when you apply.
Cognizant supports clients in many time zones and has offices across India. Answer clearly and honestly: "Yes, I am comfortable with both."
Ask about training or growth: "What does the training for GenC freshers cover, and how are projects allocated after it?" This shows interest in performing well.
Company names are trademarks of their respective owners. Interview Ready is an independent practice site and is not affiliated with or endorsed by any company listed here.