Persistent Systems Interview - Round I and II (On Campus)

Persistent Systems is a renowned global technology services company specializing in software product development and digital engineering. For engineering students participating in on-campus recruitment, Persistent typically follows a two-round interview process: Round I (Online Assessment) and Round II (Technical + HR Interview). This guide provides a detailed breakdown of each stage, including content, preparation strategies, and practical examples.

Table of Contents#

  1. Round I: Online Assessment
    1.1 Aptitude Section
    1.2 Technical MCQs
    1.3 Coding Challenges
  2. Round II: Technical Interview
    2.1 Core CS Fundamentals
    2.2 Data Structures & Algorithms
    2.3 Database Management Systems
    2.4 OOPs Concepts
    2.5 OS & Networking Basics
  3. Round II: HR Discussion
  4. Preparation Roadmap
  5. Best Practices for Success
  6. Conclusion
  7. References

1. Round I: Online Assessment#

Duration: 60-90 minutes | Platform: HackerRank/Cocubes

1.1 Aptitude Section#

Topics Covered:

  • Quantitative Reasoning (Time/Speed, Profit/Loss, Ratios)
  • Logical Reasoning (Puzzles, Sequences, Blood Relations)
  • Verbal Ability (Grammar, Vocabulary, Comprehension)

Example Question:

A train covers 120 km in 1 hour. How long will it take to cover 360 km at the same speed?
Solution: Speed = Distance/Time → Time = 360/120 = 3 hours.

Best Practices:

  • Practice quick mental math (multiplication tables, percentages).
  • Solve 5-10 puzzles daily from resources like IndiaBIX.

1.2 Technical MCQs#

Topics Covered:

  • Programming: C/C++ syntax, pointers, output prediction (e.g., int a=5; printf("%d", a++ + ++a);).
  • OOPs: Inheritance types, polymorphism, abstract classes.
  • Databases: SQL queries, normalization (1NF/2NF).
  • OS: Deadlock, scheduling algorithms (FCFS, SJF).

Example Question:

What is the output?

void main() {
  int arr[] = {1, 2, 3};
  printf("%d", *(arr + 1));
}

Solution: 2 (pointer arithmetic).

1.3 Coding Challenges#

Structure:

  • 1–2 problems (Easy/Medium difficulty).
  • Languages: C/C++, Java, Python.

Example Problems:

  1. Reverse a String (Easy): 
    def reverse_string(s):
    return s[::-1]
  2. Two-Sum (Medium): 
    public int[] twoSum(int[] nums, int target) {
    Map<Integer, Integer> map = new HashMap<>();
    for (int i = 0; i < nums.length; i++) {
        int complement = target - nums[i];
        if (map.containsKey(complement)) {
            return new int[]{map.get(complement), i};
        }
        map.put(nums[i], i);
    }
    return new int[0];
}

Best Practices:

  • Optimize for time complexity (avoid O(n²) brute-force).
  • Test edge cases: empty inputs, duplicates, large values.

2. Round II: Technical Interview#

Duration: 45–60 minutes | Mode: Face-to-Face/Virtual

2.1 Core CS Fundamentals#

Sample Questions:

  • Explain polymorphism with a real-world example.
  • Difference between threads and processes.
  • How does TCP ensure reliable data transmission?

Best Practices:

  • Relate concepts to practical projects (e.g., "I used polymorphism in my Java game project").

2.2 Data Structures & Algorithms#

Focus Areas:

  • Arrays, Strings, Linked Lists, Trees, Hashing.
  • Common algorithms: Sorting (Merge/Quick Sort), BFS/DFS.

Coding Problems:

  1. Validate a BST: 
    def isValidBST(root, low=float('-inf'), high=float('inf')):
    if not root: return True
    if root.val <= low or root.val >= high:
        return False
    return (isValidBST(root.left, low, root.val) and 
            isValidBST(root.right, root.val, high))
  2. Find loop in a Linked List:
    Use Floyd’s Cycle Detection (tortoise and hare).

2.3 Database Management Systems#

Questions:

  • Design schema for an e-commerce platform (normalize to 3NF).
  • Write a query to find the 2nd highest salary: 
    SELECT MAX(salary) FROM employees WHERE salary < (SELECT MAX(salary) FROM employees);

2.4 OOPs Concepts#

Tasks:

  • Implement inheritance for a Vehicle → Car hierarchy.
  • Explain encapsulation using getter/setter methods.

2.5 OS & Networking Basics#

Key Topics:

  • Deadlock prevention (Banker’s Algorithm).
  • HTTP vs. HTTPS.

3. Round II: HR Discussion#

Duration: 15–20 minutes
Common Questions:

  1. Why Persistent Systems?
  2. Explain a challenging team project.
  3. Where do you see yourself in 5 years?

Best Practices:

  • Research Persistent’s work in AI/cloud/healthcare.
  • Use the STAR method (Situation, Task, Action, Result) for behavioral questions.

4. Preparation Roadmap#

  1. Aptitude:
    • Books: R.S. Aggarwal (Quantitative/Logical Reasoning).
    • Websites: GeeksforGeeks, IndiaBIX.
  2. Technical MCQs:
    • Study: InterviewBit’s CS theory sections.
  3. Coding:
    • Platforms: LeetCode (50+ Easy/Medium), HackerRank.
    • Focus: Arrays, Strings, Trees (80% coverage).
  4. Theory:
    • Watch: Abdul Bari’s algorithms/OS videos.
    • Revise: DBMS normalization, SQL joins.

5. Best Practices for Success#

  1. Coding Interviews:
    • Clarify requirements first.
    • Think aloud while solving.
    • Dry run your code with examples.
  2. HR Round:
    • Highlight adaptability and teamwork.
    • Ask thoughtful questions (e.g., "How do you foster learning for new hires?").
  3. General:
    • Mock interviews with peers.
    • Maintain composure for negative marking in Round I.

6. Conclusion#

Persistent Systems’ recruitment process assesses problem-solving aptitude, technical depth, and cultural fit. Success hinges on balanced preparation across coding, fundamentals, and communication. With structured practice using resources like LeetCode and systematic theory revision, candidates can confidently tackle both rounds. Remember: Interviewers value clarity and structured thinking over perfection!

7. References#

  1. Coding Practice:
  2. Theory & MCQs:
  3. Aptitude:
  4. OOPs/DBMS Tutorials:
  5. Mock Interviews:
2026-06