Cisco is widely known as one of the largest networking and network security companies in the world, and getting an opportunity to interview with Cisco was both exciting and challenging. The entire journey — from the initial online assessment to multiple interview rounds

About me

I am a final-year Electronics and Communication Engineering (ECE) student at NIT Surat, with a strong interest in software development, problem-solving, and core programming concepts. The Cisco opportunity came through a Nationwide competition called “Code with Cisco”, which eventually led to an Intern + Full-Time Software Engineer (SWE) offer.

Phase 1 — Online Assessment (Code with Cisco)

The first stage of the process was an online assessment conducted on June 24, 2025, on the HackerRank platform. The assessment consisted of around 40 MCQ questions and two DSA problems.

The MCQs were heavily focused on core computer science fundamentals, with a strong emphasis on Computer Networks, followed by Operating Systems and OOPS. The networking questions went beyond surface-level definitions and tested conceptual understanding of how protocols work in real-world systems.

The first DSA problem was relatively advanced and revolved around computing the minimum cost to traverse a Steiner Tree. The problem required starting from a given node, visiting a set of required nodes, and ending at a specific destination while minimizing total traversal cost. The challenge was in understanding how to efficiently connect only the required nodes using the smallest possible subtree, rather than traversing the entire graph.

The second DSA problem focused on finding the minimum distance required to visit all nodes containing a specific resource. This problem tested graph traversal logic and optimization strategies to minimize redundant visits.

Overall, the assessment required strong fundamentals and calm problem-solving under pressure.

Phase 2 — Cisco Code-A-Thon Hackathon (National Finalist)

After clearing the online assessment, I was shortlisted among the Top 75 national finalists for the Cisco Code-A-Thon, a two-day hackathon held on July 17 and 18, 2025. By God’s grace, I was one of the selected participants.

The hackathon was fully sponsored by Cisco, including flight bookings, hotel stay, and logistics, which itself reflected the level of professionalism and care Cisco extends to candidates. Beyond the competition, it was an incredible experience filled with learning, collaboration, and networking. Interacting with talented peers from across the country and Cisco engineers provided exposure that went far beyond technical problem-solving.

This phase played a crucial role, as all Top 75 finalists were given the opportunity to appear for interviews.

Phase 3 — Interview Rounds (August 6, 2025)

The interview rounds were conducted on August 6, 2025, in a pool-campus-style format, using Cisco Webex platform. The interviews began early in the morning around 8:00 AM, and each round was eliminatory round.

Interview Round 1 — Technical Interview (40–45 Minutes)

The first interview began with brief introductions from both the interviewer and myself. The discussion started with a basic DSA problem, intended to assess logical clarity and coding fundamentals.

The interviewer then asked me to write and explain code demonstrating runtime and compile-time polymorphism. I implemented the example in C++, explaining concepts such as function overloading and virtual functions in a structured manner.

Following this, the discussion shifted toward Computer Networks, where I was asked about protocols such as DHCP, ARP, TCP and OSI model, including their purpose, working, and real-world usage. The round concluded with a short discussion about one of my projects.

Around 10 minutes after the interview, I received a call informing me that I had been shortlisted for the second round.

Interview Round 2 — Managerial Interview (≈1 Hour)

The second round was a managerial discussion, heavily focused on my projects and prior experience. The interviewer asked me to explain my projects in detail, starting with my first project. I discussed its relevance, unique aspects, architectural decisions, and implementation details.

A significant part of the discussion revolved around the authentication system I had built. We went deep into how tokens are generated, passed from the frontend to the backend, and verified securely. This turned into a detailed technical conversation.

We then moved to my second project, where I again explained the design and implementation. At one point, I felt myself getting nervous, so I politely asked for a moment to drink water and then resumed the discussion with better clarity.

The interview then moved to my second-year internship experience, where I explained the three major projects I worked on as a Software Development Engineer at a startup. After the interview ended, there was a tense waiting period of about 20–25 minutes, after which I received a call asking me to be available for the executive round within 5 minutes.

Interview Round 3 — Executive Interview (1–1.1 Hours)

The executive round was conducted by a highly experienced professional with around 15 years of industry experience. Despite his experience, the interviewer was extremely calm and approachable, which made the discussion comfortable.

After introductions, the discussion began with how I use AI tools like GitHub Copilot and GPT in my development workflow. He then asked about my general project workflow, which I explained using a structured SDLC approach.

An interesting part of the discussion involved prompt engineering, where I was asked to write a prompt for ChatGPT based on a project scenario he described.

The core technical part of this round involved a DSA problem similar to a phone directory system, conceptually based on the Trie data structure. The problem became more challenging when an additional constraint was introduced by him: the user might type any substring, not necessarily the prefix. For example, if the user types "for", the system should still recommend strings like "geeksforgeeks" and "geeksfortest", even though "for" appears in the middle. This constraint required deeper discussion around how to efficiently support substring-based recommendations. We had a long and engaging discussion on this problem, focusing more on thought process and approach than implementation.

The round concluded with a network security scenario, where the interviewer asked how encrypted files or messages can be detected as malicious before reaching the receiver. We discussed approaches such as behavioral analysis, metadata inspection, reputation systems, and sandboxing. The interviewer was very supportive throughout the discussion.

Before ending, I asked him questions about his team, projects, and some protocol-level discussions, which made the conversation even more insightful.

Interview Round 4 — Emerging Talent Round (15 Minutes)

At around 7:00 PM, I received a call to join the final Emerging Talent Round (ETR) within five minutes. This round was relatively lighter and more formal. The discussion involved relocation preferences, general questions about Cisco, and reflections on the hackathon experience at the Cisco office. With this round, the long interview day finally came to an end.

Final Result & Gratitude

After every round, there were tense moments where the wait felt endless. After a long wait of approximately 47 days, finally with god’s blessing I received the email extending me an Intern + Full-Time Software Engineer offer from Cisco, with a Grade 6 compensation category.

This moment is difficult to put into words. It felt like a true blessing from God and God own all the credit, definitely undoubtedly one of the most memorable days for me and my family.

Closing Thoughts

This entire journey taught me the value of patience, structured thinking, and faith in the process. Cisco’s interview process tested me technically and emotionally, but it also helped me grow significantly as an engineer and as a person.

I am deeply grateful for this opportunity and the learnings that came with it.

Written by Yash Patel