19 questions · from 2 interviews
Qualys interview questions
Every question candidates reported from their Qualys interviews, most frequently asked first. Each links to the write-up it came from, so you can see the round and how it went.
Qualys coding and DSA questions
- 01
Linked List Cycle II
Detect a cycle in a linked list and return the node where the cycle begins. Explain the approach, time complexity, and space complexity.
Medium · From Qualys Interview Experience | Software Engineer | 4 Rounds
- 02
Valid Parentheses
Check whether a string containing brackets is valid. Explain the time and space complexity.
Easy · From Qualys Interview Experience | Software Engineer | 4 Rounds
- 03
Rotate Array
Rotate an array to the right by k steps, where k is non‑negative. Explain the different approaches and their exact time and auxiliary space complexities. Discuss the reversal algorithm in detail, including why it performs three reversals and how many…
Easy · From Qualys Interview Experience | Software Engineer | 4 Rounds
- 04
Doubly Linked List – Delete Node
Delete a node at a given position in a doubly linked list. Explain the approach, time complexity, and auxiliary space complexity.
Medium · From Qualys Interview Experience | Software Engineer | 4 Rounds
- 05
Doubly Linked List – Insert Node
Insert a node at a given position in a doubly linked list. Explain the approach, time complexity, and auxiliary space complexity.
Medium · From Qualys Interview Experience | Software Engineer | 4 Rounds
- 06
Binary Search
Explain binary search, its implementation, and its time and space complexity.
Easy · From Qualys Interview Experience | Software Engineer | 4 Rounds
- 07
Top K Frequent Elements
Given an integer array nums and an integer k , return the k most frequent elements in nums . The order of the returned elements does not matter.
Medium · From Qualys Interview Experience for SE2 Java
- 08
Anagram Check
Given two strings s1 and s2 , determine whether s2 is an anagram of s1 . Return true if they are anagrams, otherwise return false .
Easy · From Qualys Interview Experience for SE2 Java
Qualys other questions
- 01
Explain HNSW Algorithm
Explain the HNSW (Hierarchical Navigable Small World) algorithm.
From Qualys Interview Experience | Software Engineer | 4 Rounds
- 02
Write POST API Method
Explain REST APIs and write a POST API method.
From Qualys Interview Experience | Software Engineer | 4 Rounds
- 03
Java Multithreading Concepts
Explain Java multithreading and its concepts.
From Qualys Interview Experience | Software Engineer | 4 Rounds
- 04
HTTP Status Codes
What are the different HTTP status codes?
From Qualys Interview Experience | Software Engineer | 4 Rounds
- 05
SQL Constraints
What are constraints in SQL?
From Qualys Interview Experience | Software Engineer | 4 Rounds
- 06
SQL Query Writing
Write SQL queries based on the given requirements.
From Qualys Interview Experience | Software Engineer | 4 Rounds
- 07
Multi‑Agent System Explanation
Explain how a multi‑agent system works.
From Qualys Interview Experience | Software Engineer | 4 Rounds
- 08
Supervisor and Subagent Communication
What are a supervisor agent and subagents? How do they communicate, delegate tasks, and coordinate their execution?
From Qualys Interview Experience | Software Engineer | 4 Rounds
- 09
DNS Explanation
What is DNS, and how does it work?
From Qualys Interview Experience | Software Engineer | 4 Rounds
- 10
DHCP Explanation
What is DHCP, and why is it required?
From Qualys Interview Experience | Software Engineer | 4 Rounds
- 11
Laptop Troubleshooting Steps
Your laptop is running slowly. How would you troubleshoot the issue step by step?
From Qualys Interview Experience | Software Engineer | 4 Rounds
Qualys interview questions FAQ
What questions are asked in Qualys interviews?
Candidates reported 19 distinct questions across 2 Qualys interviews. 8 coding and DSA questions, 11 other questions.
How difficult are Qualys interview questions?
Of the questions candidates rated, 50% were easy, 50% medium and 0% hard.