SquadStack.ai Core Engineer On-Campus Experience

I recently went through the SquadStack.ai Core Engineer on-campus hiring process.

Four stages, each one tested something different from aptitude and DSA to CS fundamentals, system thinking and behavioral discussions.

I cleared all four stages and was selected for the Winter Internship + FTE opportunity.

Round-by-Round Experience

Round 1: Online Assessment

My first stage was an OA covering logical reasoning, quantitative aptitude and basic CS fundamentals, along with two coding problems and one SQL question.

For the first coding problem, I had to find the minimum-length contiguous subarray whose sum was at least a given target. I initially thought about checking different subarrays, but since all values were positive, I used a sliding-window approach.

The second problem was Longest Increasing Subsequence. I first discussed the O(n²) DP solution and then explained how I could optimize it to O(n log n) using binary search.

For SQL, I had to combine multiple tables using a JOIN, group the records and apply an aggregate condition.

Round 2: Technical Interview

After clearing the OA, I had my main technical round.

I was asked questions from Operating Systems, DBMS, Computer Networks and OOP. Some of the topics I discussed were processes vs threads, deadlocks, database indexes, TCP vs UDP, abstraction vs encapsulation, and method overloading vs overriding.

I also solved two DSA problems.

The first was Longest Consecutive Sequence. I started with sorting and then improved my solution to O(n) using a HashSet.

The second was Merge K Sorted Linked Lists. I used a min-heap to keep track of the smallest available node from each list.

After explaining my solutions, I also discussed their time complexity and how they would behave for larger inputs.

Round 3: System Discussion

My third round was more focused on system-level thinking.

I don't remember the exact design question clearly. What I do remember is that I had to understand the requirements, break the problem into smaller components and explain how those components would interact.

Round 4: Culture Fit and HR

My final round was much more conversational.

I talked about my projects, technical challenges I had faced and situations where I had disagreements while working with others.

I was also asked about a project I was proud of, what I expected from my first full-time engineering role, why I wanted to join SquadStack.ai, and where I wanted to grow over the next few years.

Interview Result

After completing all stages, I received the confirmation that I had been selected for the Winter Internship + FTE opportunity.

For me, DSA preparation was definitely useful, especially patterns like sliding window, hashing, DP, binary search and heaps.

Preparation Tips

Based on my experience, I would suggest revising OS, DBMS, CN and OOP fundamentals along with DSA.

I would also practise SQL joins and aggregation problems and prepare my projects properly not just what I built, but why I made certain technical decisions and what I would change if the requirements were different.