NxtWave SDI Internship Interview Experience — August 27, 2026

I interviewed for the SDI (Software Development Instructor) Internship at NxtWave. I got the opportunity through an email from NxtWave and applied through the application form.

The role involved offline teaching for a batch of around 60–70 students. The package mentioned was around 8–12 LPA.

The interview process had 3 rounds.

Round 1 — Telephonic HR

Date: August 27, 2026

HR called and told me that my profile was shortlisted.

Questions asked:

Tell me about yourself. What do you know about the SDI role? Do you have any teaching experience? Why are you interested in this role? What are your expected CTC?

It was a basic HR screening round.

Round 2 — DSA Coding

The interviewer asked me to open LeetCode and solve coding problems while explaining my approach.

Interview Setup

I had to join using both a laptop and mobile phone.

Laptop was used for the interview, coding, and screen sharing. Mobile camera had to be switched on and positioned toward the laptop/desk. This setup was used to ensure a fair interview process and prevent cheating or external assistance. Question 1 — Count Islands With Total Value Divisible by K

https://leetcode.com/problems/count-islands-with-total-value-divisible-by-k/description/

I was able to solve the problem, explain my approach, and give the time complexity.

Question 2 — Minimum Number of Arrows to Burst Balloons

https://leetcode.com/problems/minimum-number-of-arrows-to-burst-balloons/description/

I had already solved this problem before, so the interviewer changed the question to test my understanding.

Question 3 — Minimum Genetic Mutation

https://leetcode.com/problems/minimum-genetic-mutation/description/

I explained the brute-force and optimal approaches, implemented the solution, and submitted it on LeetCode within around one hour.

I was also able to explain the time and space complexity.

Round 3 — Managerial + Technical

The next day, HR called and told me that I was selected for the third round with a manager.

HR told me:

There would be no DSA coding question because I had already solved two coding questions in Round 2. There would be rapid-fire questions. The interview would be around 30 minutes. Topics to prepare: Hash Tables Heaps Tries Segment Trees Interview Setup

The same laptop + mobile camera setup was followed in this round as well.

I joined through my laptop for the interview, while my mobile camera was switched on and positioned toward my laptop/desk.

Questions Asked

The interviewer first asked for my introduction and went through my internship experience.

He noticed that I hadn't mentioned Codeforces on my resume and asked why.

I explained that I had used Codeforces earlier but later shifted my focus to LeetCode.

Then he asked rapid-fire DSA questions.

Questions included: What are Heaps? What is Divide and Conquer? What is Merge Sort? What is GCD? What is gcd(a,b)? What is a Segment Tree?

He also asked about the Euclidean algorithm:

a = quotient × b + remainder

and the complexity of GCD:

O(log(min(a,b)))

Bit Manipulation

He asked basic bit-manipulation questions such as: Check i-th bit Set i-th bit Clear i-th bit Toggle i-th bit Count set bits Heapify

The interviewer went deeper into heaps and asked: What is heapify? How does heapify work? How are elements arranged internally? What happens when the root element is removed? How does the heap rearrange itself? What is the time complexity?

He asked me to open a heap example and explain how the internal array changes after removing the root and how the heapify process restores the heap property.

I was not able to explain this properly.

Divide and Conquer / Merge Sort

He also asked me to explain: What is Divide and Conquer? How does Merge Sort use it? How does Merge Sort work? What is its time complexity?

Teaching Aspect

Since this was an SDI role, the interview also focused on how I would handle questions while teaching.

The interviewer wanted to know how I would approach a situation where a student asks a question that I don't know immediately.

The focus was on how I would: Understand the question. Think through the problem. Explain my approach. Arrive at an answer. Overall Experience

Round 1: Straightforward HR round. Round 2: DSA coding round went well. I was able to solve and explain the questions. Round 3: More difficult. There were rapid-fire questions on DSA fundamentals, and I struggled with some of them, especially heapify and the internal working of heaps.

The round also tested whether I could explain concepts clearly and handle unfamiliar questions, which is important for an instructor role.

I am currently waiting for the result from NxtWave.