Pubmatic

Role: SDE (Software Development Engineer)

College: Not Specified (On-Campus)

Interview Date: October 1, 2024

Interview Type: On-Campus, Full-Time

Result: Not Specified

Difficulty: Not Specified

Rounds: 3 rounds

Topics Asked: OOP, DBMS, OS, CNS, Data Structures, Algorithms, Linux commands (though candidate not familiar), Abstraction, Virtual function, Pure virtual function, Hashmap, Searching and Sorting algorithms (Quick sort, Merge sort TC/SC), B-trees, Mutex, Semaphore, Multithreading, Resume-based, General discussion.

Experience:

Pubmatic visited the campus for a recruitment drive.

Round 1: Online Assessment
This was a 90-minute HackerRank test comprising MCQs based on core subjects like OOP, DBMS, OS, CNS, and Data Structures and Algorithms, along with 2 coding questions. One coding question was LeetCode easy, and the other was LeetCode hard. The candidate passed all test cases for the easy question and 9/14 for the hard one. After this OA, 14 students from the college were selected for the interview rounds.

Round 2: Technical Round-1
The questions were resume-based and included a general discussion about education and hometown. The interviewer asked about OOP concepts like Abstraction, Virtual functions, and Pure virtual functions, and asked the candidate to write a piece of code on paper. A situational question was posed, asking which Data Structure could be used for efficient data retrieval, with Hashmap being the answer. The interviewer also asked about Linux commands, but the candidate was not familiar.

Round 3: Technical Round-2
This round included questions on checking for anagrams, designing a malloc system, and reversing a string without reversing words (e.g., "I am good" -> "good am I"). Building a binary search tree was also discussed. The candidate was asked to explain searching and sorting algorithms they knew, specifically the differences between Quick sort and Merge sort, including their time and space complexities. Questions about B-trees were asked, but the candidate was unable to recall them at the moment. Some OS questions like Mutex, Semaphore, and multithreading were repeated.

Tip: Have a strong hold on DSA and OS.