I applied for a winter internship at Cisco through cold emailing an HR representative, expressing my interest and providing my resume. A few hours later, she responded, asking for my availability for interview slots. The interview process consisted of three rounds, including two technical rounds.

In the first round, which focused on problem-solving, the interviewer started with introductions. He introduced himself first and then asked me to introduce myself. Afterward, he quickly moved on to basic Computer Networks theory questions, which is expected from Cisco. He inquired about routers, how they work, subnetting, subnet masks, and other theoretical questions that I can't recall in detail. Most of the questions were related to Computer Networks.

Then, he asked me to share my screen and provided a Codepair link in the comment section for a problem-solving task. The problem statement was extensive and related to router operations. It described a scenario where a router functions for a period, becomes idle, and then resumes operation. The task was to find all the idle intervals. The problem was essentially an array implementation task, similar to a Leetcode medium problem. I explained my thought process to the interviewer, and he seemed convinced. He then asked me to code the solution. Although I solved the problem, it took some time, which made me a bit stressed as there was another problem to solve.

The next problem also had a lengthy statement involving routers, but it ultimately boiled down to the "merge overlapping intervals" problem on Leetcode. I solved this one in less time.

With some time remaining, the interviewer shifted back to CS fundamentals. He asked basic C questions, like about malloc, and some operating system concepts. That concluded the first round.

Verdict: Selected in the first round.

Will tell about the next round interview experience in 2nd post.