41 questions · from 3 interviews
Persistent Systems interview questions
Every question candidates reported from their Persistent Systems interviews, most frequently asked first. Each links to the write-up it came from, so you can see the round and how it went.
Persistent Systems coding and DSA questions
- 01
Reverse a String
Write a program to reverse a string.
Easy · From Persistent Systems — Senior Telecom Software Developer Interview Experience
- 02
Convert Binary String by Reversing Substrings
Given two binary strings (strings of '0's and '1's) A and B. Convert string A to string B by selecting any substring and reversing it. The size of the substring selected in the current operation must be greater than the previously selected substring size.…
From persistent systems | on-campus 2021 | online assessment questions | interview questions
- 03
Edge in Graph with Max Simple Paths
Given an undirected graph, find the edge which is part of the maximum number of simple paths.
From persistent systems | on-campus 2021 | online assessment questions | interview questions
- 04
Print Pascal Triangle
Write code to print the Pascal's Triangle.
Easy · From persistent systems | on-campus 2021 | online assessment questions | interview questions
- 05
Sort Array by Frequency with Order Preservation
Given an integer array, sort the elements by frequency. If the frequency is the same, then the element which occurs first in the original array comes first in the sorted array.
Medium · From persistent systems | on-campus 2021 | online assessment questions | interview questions
- 06
What are Heaps?
What are heaps?
Easy · From persistent systems | on-campus 2021 | online assessment questions | interview questions
- 07
Explain Selection Sort
Explain the Selection Sort algorithm.
Easy · From persistent systems | on-campus 2021 | online assessment questions | interview questions
- 08
Number of Islands
The problem was the same as the 'Number of Islands' problem on LeetCode.
Medium · From persistent systems | on-campus 2021 | online assessment questions | interview questions
- 09
Variation of Connected Components in Undirected Graph
A variation of finding connected components in an undirected graph, which was not as straightforward as the previous problem.
Medium · From persistent systems | on-campus 2021 | online assessment questions | interview questions
- 10
What is Recursion?
What is recursion?
Easy · From persistent systems | on-campus 2021 | online assessment questions | interview questions
- 11
Types of Recursion & Tail Recursion Optimization
What are the different kinds of recursion? How is tail recursion made equivalent to a while loop by the compiler?
Hard · From persistent systems | on-campus 2021 | online assessment questions | interview questions
- 12
Explain Bubble Sort
Explain the Bubble Sort algorithm, how it works, and its characteristics.
Easy · From Persistent Systems Interview Experience (On-campus 2021 Batch)
- 13
Reformat Date YY/MM/DD to DD/Month/YYYY
Convert an input date string from YY/MM/DD format to DD/MonthString/YYYY format. For example, convert 2020/12/26 to 26/December/2020.
Medium · From Persistent Systems Interview Experience (On-campus 2021 Batch)
Persistent Systems system design questions
- 01
Word Frequency in Huge Text File
Given a huge text file, how would you find word frequency? (Note: reading the file in chunks and using a hashmap was not the desired approach.)
Hard · From persistent systems | on-campus 2021 | online assessment questions | interview questions
Persistent Systems other questions
- 01
SQL: Create Table
Write a SQL query to create a table.
Easy · From persistent systems | on-campus 2021 | online assessment questions | interview questions
- 02
SQL: Insert into Table
Write a SQL query to insert data into a table.
Easy · From persistent systems | on-campus 2021 | online assessment questions | interview questions
- 03
SQL: Find Duplicates by Two Columns
Given a table with three columns, write a SQL query to find duplicates with respect to the first two columns. (Hint: can be solved using GROUP BY and HAVING clause).
Medium · From persistent systems | on-campus 2021 | online assessment questions | interview questions
- 04
Pointers vs. References (C++)
What is the difference between pointers and references (assuming C++ context)?
Medium · From persistent systems | on-campus 2021 | online assessment questions | interview questions
- 05
Disadvantages of Waterfall Model
What are the disadvantages of the Waterfall model?
Easy · From persistent systems | on-campus 2021 | online assessment questions | interview questions
- 06
Array Declaration Syntax (Java/C#)
What is the difference between int var[]; and int[] var; ?
Medium · From persistent systems | on-campus 2021 | online assessment questions | interview questions
- 07
What are Exceptions?
What are exceptions?
Easy · From persistent systems | on-campus 2021 | online assessment questions | interview questions
- 08
Exceptions vs. Errors
What are the differences between exceptions and errors?
Medium · From persistent systems | on-campus 2021 | online assessment questions | interview questions
- 09
SQL Self Join Problem
A simple problem requiring the use of SQL self join.
Easy · From persistent systems | on-campus 2021 | online assessment questions | interview questions
- 10
What is Context Manager in Python?
What is a context manager in Python?
Medium · From persistent systems | on-campus 2021 | online assessment questions | interview questions
- 11
What is GIL in Python?
What is the Global Interpreter Lock (GIL) in Python?
Hard · From persistent systems | on-campus 2021 | online assessment questions | interview questions
- 12
While Loop vs. Recursion Efficiency
How is a while loop generally more efficient with respect to recursion?
Medium · From persistent systems | on-campus 2021 | online assessment questions | interview questions
- 13
Layers in Network Architecture
What are the layers in a network architecture (e.g., OSI model or TCP/IP model)?
Medium · From persistent systems | on-campus 2021 | online assessment questions | interview questions
- 14
Reliable Transmission Layer
Which layer in network architecture is responsible for reliable transmission?
Easy · From persistent systems | on-campus 2021 | online assessment questions | interview questions
- 15
Functions of Transport and Network Layers
What are the functions of the Transport Layer and Network Layer in network architecture?
Medium · From persistent systems | on-campus 2021 | online assessment questions | interview questions
- 16
What are Indexes in RDBMS?
What are indexes in a Relational Database Management System (RDBMS)?
Medium · From persistent systems | on-campus 2021 | online assessment questions | interview questions
- 17
Types of Indexes in RDBMS
What are the different kinds of indexes in RDBMS?
Hard · From persistent systems | on-campus 2021 | online assessment questions | interview questions
- 18
Explain Bias-Variance Tradeoff
Explain the bias-variance tradeoff in machine learning.
Medium · From persistent systems | on-campus 2021 | online assessment questions | interview questions
- 19
Explain Normalization (ML/Statistics)
Explain normalization (in the context of machine learning or statistics).
Medium · From persistent systems | on-campus 2021 | online assessment questions | interview questions
- 20
Explain OOPS Concepts
Explain the fundamental concepts of Object-Oriented Programming Systems (OOPS).
From Persistent Systems Interview Experience (On-campus 2021 Batch)
- 21
C++ vs Java Differences
Explain the key differences between C++ and Java programming languages.
From Persistent Systems Interview Experience (On-campus 2021 Batch)
- 22
Database Normalization Purpose
Explain the purpose and importance of database normalization.
From Persistent Systems Interview Experience (On-campus 2021 Batch)
- 23
Inner Join vs Outer Join
Explain the difference between Inner Join and Outer Join in SQL/databases.
From Persistent Systems Interview Experience (On-campus 2021 Batch)
- 24
Abstract Class vs Interface
Explain the key differences between abstract classes and interfaces in object-oriented programming (e.g., Java).
From Persistent Systems Interview Experience (On-campus 2021 Batch)
- 25
Java Access Specifiers
Explain the concept and types of access specifiers (modifiers) in Java.
From Persistent Systems Interview Experience (On-campus 2021 Batch)
2 more in the Persistent Systems write-ups.
Persistent Systems interview questions FAQ
What questions are asked in Persistent Systems interviews?
Candidates reported 41 distinct questions across 3 Persistent Systems interviews. 13 coding and DSA questions, 1 system design questions, 27 other questions.
How difficult are Persistent Systems interview questions?
Of the questions candidates rated, 39% were easy, 48% medium and 13% hard.