PhonePe

Role: Software Engineer

College: PEC – Chandigarh

Interview Date: Aug 2022

Interview Type: On-Campus

Result: Not Specified

Difficulty: Hard

Rounds: 4 rounds

Topics Asked: Data Structures, Algorithms, C++ (Stack vs Heap, Inheritance, Virtual Function/Class), Operating Systems (Deadlock), Project Discussion

Experience:

This on-campus interview process at PhonePe, conducted in August 2022, consisted of four rounds and was generally considered hard. The first round was an Online Test (90 minutes) conducted on the DoSelect Platform, comprising 4 coding questions, all deemed "HARD" level. The questions were given in random order of difficulty. One problem was about determining if "array b is the most sad array possible," with a logic similar to a known problem but difficult language. Another was a variation of a graph coloring problem where the goal was to color a graph at minimum cost given 4 colors and their costs. The candidate was able to pass 7 out of 10 test cases for the first question and 7 out of 9 for the graph coloring problem. The cutoff for this round was 13 test cases, and 18 out of 181 candidates were shortlisted.

Round 2 was a Technical Round (60 minutes) with two interviewers, also rated "HARD". After an introduction, the interview focused on DSA. The first question was to find the maximum area rectangle in a binary matrix. The candidate initially explained a brute-force O(N^2) approach, then optimized it to O(N) using a Stack. After the interviewers pointed out some failing test cases, the candidate corrected the code, satisfying both interviewers. 11 out of 18 candidates were shortlisted for the next round.

Round 3, another Technical Round (60 minutes) and "HARD", directly proceeded to DSA questions without introductions. One question involved a scenario with 12 rats, where the candidate could come up with a solution for up to 36 rats but not an exact solution beyond that. The interviewer agreed that the answer would lie in the 36-48 range. Following this, CS subject questions were asked, including differences between Stack and Heap memory, inheritance, virtual functions and classes in C++ and their applications, and deadlock conditions and scenarios. For another problem, the candidate explained a recursive brute-force approach, which satisfied the interviewer. For a second question, the candidate explained the complete approach and what `dp[i][j]` would store, but couldn't write the complete code, though the interviewer was satisfied with the approach. 5 out of 11 were shortlisted for the next round.

Round 4 was scheduled as an HR round but turned into an HR + Technical Round (70 minutes) and was also "HARD". The candidate was asked in-depth about their project, an E-Commerce Web Application using Django REST Framework.