82 questions · from 18 interviews · 1 asked more than once
Cisco interview questions
Every question candidates reported from their Cisco interviews, most frequently asked first. Each links to the write-up it came from, so you can see the round and how it went.
Cisco coding and DSA questions
- 01
Linked List Deletion and Reversal
During my first technical round, I was presented with a coding challenge focused on Linked Lists. The problem required me to implement operations for both deleting specific nodes and reversing the entire linked list efficiently. I had to demonstrate my…
Medium · Asked 2 times · From CISCO Internship
- 02
Find Duplicate in List of Numbers
Given a list of integers, determine whether any number appears more than once in the list. Return true if a duplicate exists, otherwise return false.
Easy · From Cisco Engineer Manager Round-2
- 03
Sliding Window Array Manipulation
Array manipulation involving a sliding window. The problem was similar to "Grumpy Bookstore Owner."
Medium · From Cisco SDE2 | Bangalore | Interview Experience
- 04
Minimum Time to Broadcast Message in Network
Given a network of routers, find the minimum time to broadcast a message to all nodes (Dijkstra’s variant).
Medium · From Cisco SDE2 | Bangalore | Interview Experience
- 05
Lowest Common Ancestor (LCA) in a Binary Tree
Find the Lowest Common Ancestor (LCA) in a Binary Tree. I discussed both the recursive approach and an iterative approach using parent pointers.
Medium · From Cisco SDE2 | Bangalore | Interview Experience
- 06
Longest Palindromic Substring
Find the "Longest Palindromic Substring."
Medium · From Cisco SDE2 | Bangalore | Interview Experience
- 07
Smallest Subarray with Sum Greater Than X
Find the smallest subarray with sum greater than X.
- 08
Minimum Platforms for Trains
Determine the minimum number of platforms required for trains.
- 09
Next Greater Element to Right
I was asked to find the next greater element to the right for each element in an array.
Medium · From Cisco | Interview Experience | Ghosted
- 10
Group Anagrams
I was asked to group anagrams together from a given list of strings.
Medium · From Cisco | Interview Experience | Ghosted
- 11
Reverse Linked List II
I was asked to reverse a linked list from position m to n.
Medium · From Cisco | Interview Experience | Ghosted
- 12
Maximum Subarray
I was asked the LeetCode Medium difficulty question, Maximum Subarray.
Medium · From CISCO SDE interview experience
- 13
Fibonacci using Go Routines and Channels
I was asked to write a Fibonacci program in Go using channels and goroutines, demonstrating understanding of Go's concurrency primitives like unbuffered and buffered channels, mutexes, and waitgroups.
- 14
Linked List: Delete and Reverse
The problem involved operations on a Linked List, specifically deletion and reversal of elements.
- 15
Floyd-Warshall Algorithm Application
A problem requiring the application of the Floyd-Warshall algorithm.
- 16
Binary Search Problem
A problem that could be solved using binary search.
- 17
DP Problem similar to Burst Balloons
During the online assessment, I encountered a medium-level dynamic programming problem. It was described as being similar to LeetCode's Burst Balloons problem, which involves maximizing the coins collected by bursting balloons. While the exact problem…
Medium · From Cisco | Software Engineer - New Grad | Bengaluru | Nov 2022 [OFFER]
- 18
Clone List with Random Pointer
A linked list of length n is given such that each node contains an additional random pointer, which could point to any node in the list, or null. // For example: // 1(4)->2(null)->3(2)->4(null) / // Definition for a Node. class Node { int val; Node…
- 19
Three Sum
Standard LeetCode Three Sum question. It is recommended to check all variations of this problem.
- 20
Check if Number is Power of 2
Given an integer, write a function to determine if it is a power of two. Implement the code in C.
Easy · From CISCO INTERSHIP QUESSTION & PROCESS
- 21
Search in Rotated Sorted Array
Given a sorted array that has been rotated some number of times, and a target number, write an efficient code to determine if the target number is present in the array.
Medium · From CISCO INTERSHIP QUESSTION & PROCESS
- 22
Implement Quick Sort
Implement the Quick Sort algorithm. I struggled with this initially, but the interviewer was very helpful and explained the concept with an example.
Medium · From CISCO INTERSHIP QUESSTION & PROCESS
- 23
Swap Adjacent Nibbles
Given a number, write efficient code in your favorite language to swap adjacent nibbles (four bits consecutively). Initially, I came up with an unoptimized solution and was prompted to optimize it, with a hint about using bitwise operators.
Medium · From CISCO INTERSHIP QUESSTION & PROCESS
- 24
Character Frequency Counter
Given a string, write efficient code to count the frequency of each character in that string. I initially explained one method and was then asked to optimize it further.
Easy · From CISCO INTERSHIP QUESSTION & PROCESS
- 25
Count Nodes in Binary Tree
Write a function to count the total number of nodes in a given binary tree.
2 more in the Cisco write-ups.
Cisco system design questions
- 01
Design a Network Monitoring System
Design a simplified "Network Monitoring System" that can handle logs from 10,000+ devices. Keywords discussed: Kafka for ingestion, Time-series DB (InfluxDB), and Load Balancing.
Hard · From Cisco SDE2 | Bangalore | Interview Experience
- 02
Design a Rate Limiter Library
Design a "Rate Limiter" as a library.
Medium · From Cisco SDE2 | Bangalore | Interview Experience
- 03
Design a Chat/Helping System
Design a chat/helping system.
From Cisco FY’26 || Winter Intern + FTE || Detailed Interview Experience || Off campus
- 04
Networking Concepts Discussion
Discussion on networking concepts including TCP/UDP, three-way handshaking, and the distinctions between routers and switches.
- 05
Design Netflix
Design a system similar to Netflix. I confessed my knowledge gap on this topic.
- 06
System Design: AI/ML Powered Delivery Application
Design an 'X Application' (name not revealed) considering its functionality and how it leverages AI/ML. Specifically, elaborate on: How the inventory system operates. How delivery personnel are assigned using AI. Strategies to ensure product delivery within a…
Hard · From Cisco | SDE Intern Interview Experience | [Rejected] (Tier 3 Student)
- 07
Design a Vending Machine
I was tasked with designing a vending machine system, considering aspects like user interaction points, payment processing, and inventory management. Additionally, I had to outline a comprehensive set of test cases for the design.
From Cisco | Software Engineer | Bangalore | December 2021 | Accept
- 08
Design an API Framework for Logging
I needed to design an API framework for logging, specifically leveraging Linux commands for its implementation.
From Cisco | Software Engineer | Bangalore | December 2021 | Accept
Cisco behavioural and HR questions
- 01
Conflict with a Teammate
Describe a situation where you had a conflict with a teammate.
- 02
Where do you see yourself in the next 3-4 years?
Where do you see yourself in the next 3–4 years?
From Cisco FY’26 || Winter Intern + FTE || Detailed Interview Experience || Off campus
- 03
Project Not Going as Planned
Tell me about a time when things didn’t go as planned in a project.
- 04
Handling Unknowns and Delivery Expectations
How do you handle it when you don’t know something but are expected to deliver?
- 05
Biggest Challenge Leading a Team
What’s the biggest challenge you’ve faced while leading a team?
- 06
Data-Backed Decision Making
How would you use data to identify trends or drive improvements in a business process?
- 07
- 08
- 09
- 10
- 11
Why Take Role Immediately After Graduation?
Why do you want to take up a role immediately after graduation?
- 12
Career Aspirations
In the HR round, I was asked, 'Where do you see yourself in 5 years?'
- 13
Knowledge of Cisco
The HR interviewer asked, 'What do you know about Cisco?'
- 14
Personal Background (Father's Education)
The HR interviewer asked, 'Tell me about your father’s education.'
- 15
Thoughts on Stipend and Location
The HR interviewer asked, 'What are your thoughts on the offered stipend and location?'
- 16
Behavioral: Where do you see yourself in 5 years?
The HR personnel asked, "Where do you see yourself in 5 years?"
- 17
Behavioral: What do you know about Cisco?
The HR personnel asked, "What do you know about Cisco?"
- 18
Behavioral: Tell me about your father's education
The HR personnel asked, "Tell me about your father’s education."
- 19
Behavioral: Thoughts on stipend and location
The HR personnel asked, "What are your thoughts on the offered stipend and location?"
- 20
Personal Strengths and Weaknesses
What are your personal strengths and weaknesses?
- 21
Salary and Location Preferences
Discussion regarding salary expectations and internship location preferences.
- 22
Conflict Resolution
I was asked to describe my approach to solving a conflict, likely in a team or work environment.
From Cisco | Software Engineer | Bangalore | December 2021 | Accept
- 23
Career Aspirations and Company Fit
I discussed my greatest accomplishments, my motivations for wanting to join Cisco, my knowledge of Cisco's competitors, future plans for higher studies, and any current job offers.
From Cisco | Software Engineer | Bangalore | December 2021 | Accept
- 24
Why Hire You for a Non-AI Role
The manager challenged me on why I should be hired given that my primary interest (AI/ML/DL) does not align with their department's current work.
- 25
Behavioral Questions
I was asked several standard behavioral questions, including my motivation for switching companies, why I was interested in Cisco, and how I envisioned myself fitting into the specific role.
Cisco other questions
- 01
How Traceroute Works
Deep dive into how a Traceroute works.
- 02
Difference between TCP and UDP Headers
Explain the difference between TCP and UDP headers.
- 03
- 04
- 05
How ConcurrentHashMap Works Internally
Explain how ConcurrentHashMap works internally in Java.
- 06
Experience with CI/CD Pipelines
What is your experience with CI/CD pipelines (Jenkins/GitLab CI)?
- 07
Cisco's Shift to Software-Defined Networking (SDN)
Discussion on Cisco’s shift toward "Software-Defined Networking" (SDN).
- 08
News Channel vs Newspaper Discussion
Participants were given a random topic and had to speak for about 90 seconds. My topic was 'News Channel vs Newspaper'. I focused my speech on the importance of authenticity over medium, emphasizing that credibility of information matters more than the format…
- 09
Difference between SSH and TLS
I was asked to explain the difference between SSH and TLS.
- 10
Inner Join vs Outer Join in Databases
I was asked to explain the difference between Inner Join and Outer Join in databases.
- 11
Database Transactions and ACID Properties
I was asked about transactions and their uses in databases, which led to explaining ACID properties.
- 12
OSI Model
I was asked questions related to the OSI Model, a fundamental concept in computer networks.
From Cisco | Technical Consulting Engineer | Bengaluru | Nov 2023 [Offer]
- 13
Network Ports
Questions were posed regarding network ports, their function, and common uses.
From Cisco | Technical Consulting Engineer | Bengaluru | Nov 2023 [Offer]
- 14
TCP Connection
I faced questions about the TCP connection process, likely covering topics such as the three-way handshake and connection states.
From Cisco | Technical Consulting Engineer | Bengaluru | Nov 2023 [Offer]
- 15
Extend To-Do List Application
During my technical interview, I was asked to showcase a To-Do List application I had recently worked on. The interviewer then tasked me with implementing additional functionalities within this existing project.
- 16
NoSQL vs SQL Database Concepts
Discussion on the differences between NoSQL and SQL databases, including concepts like sharding and distribution.
- 17
- 18
Debugging Microservices
Questions on how I would approach debugging microservices.
- 19
Browser Navigation for www.cisco.com
I was asked to describe the sequence of events and underlying protocols involved when a user types "www.cisco.com" into a web browser and hits enter.
From Cisco | Software Engineer | Bangalore | December 2021 | Accept
- 20
- 21
Car Wheel Longevity Puzzle
A car has four new wheels and one new spare wheel (Stepney). Each wheel can run for a maximum of 20,000 km. Calculate the maximum distance the car can run.
Medium · From CISCO INTERSHIP QUESSTION & PROCESS
- 22
Design Generic Data Structure in C
How would you design a generic structure in C that can hold any type of data?
Cisco interview questions FAQ
What questions are asked in Cisco interviews?
Candidates reported 82 distinct questions across 18 Cisco interviews. 27 coding and DSA questions, 8 system design questions, 25 behavioural and HR questions, 22 other questions.
Which Cisco interview questions are asked most often?
The most repeated are "Linked List Deletion and Reversal" (2 times).
How difficult are Cisco interview questions?
Of the questions candidates rated, 15% were easy, 75% medium and 10% hard.