PubMatic Software Engineer Interview Questions
& Process
Real candidates share what happened, how many rounds they had,
and how the experience turned out.
Based on 61 interview experiences · FREE TO READ
Candidate interview experiences
First-hand accounts from people who interviewed at PubMatic.
PubMatic
Software Engineer
Entry Average Positive experience Accept offer 3 rounds
Interview process
Technical screen Technical screen Onsite
Interview formats
Coding Technical System Design
Applied through a LinkedIn referral. I have 1.3 years of experience. The interview process had 3 rounds. Round 1 involved 2 DSA questions: rotating an array at index k and finding a loop in a linked list. There were also questions on core Java and Spring Boot, covering Spring MVC architecture, scaling a project to a million users, Java Streams, OOPS, database indexing, and resume-based questions. Round 2 had one DSA question about finding the winner in an NxN tic-tac-toe board. Java and Spring questions included multithreading (avoiding race conditions, implementations), bean scope, Singleton design pattern, indexing and B-trees, DFS implementation (pseudo-code), anomaly detection, and the diamond problem in Java. Round 3 was focused on Low-Level Design (LLD) for a snake and ladder game, scaling a system to a million users, project Q&A, and a general discussion about GenAI.
Confirmed questions2 questions
- Questions about resume and scalability
- Questions about resume and scalability
PubMatic
Software Engineer
Mid Easy Neutral experience No offer 4 rounds
Interview process
Recruiter call Technical screen Onsite
Interview formats
Technical Coding Behavioral
GenAI interview had 3 rounds plus 1 in-person, totaling 4 rounds. The first round had an easy DSA question (2 pointers) and questions about my projects and experience. The second round focused on RAG implementation and a DSA question (sliding window), where I was asked to implement a text splitter similar to langchains. The interviewer struggled to frame the question clearly and seemed to follow a random approach. Despite this, I solved the question, which seemed to provoke the interviewer. He abruptly turned off the recording and rudely ended the interview. It really shows how interview experiences can depend on someone's mood, even if you have the skills. I considered reporting this to HR, but decided against it, as the interaction gave me a good insight into the person and the team.
Confirmed questions3 questions
- Tell me about your projects and experience, and solve an easy DSA problem using the 2-pointer technique.
- Can you implement RAG and solve a DSA question involving sliding windows, specifically by implementing a text splitter for a given text?
- Let's dive deep into Generative AI.
PubMatic
Software Engineer Intern
Intern Average Positive experience No offer 5 rounds
Interview process
Recruiter call Technical screen Technical screen Onsite Onsite
Interview formats
Coding Technical System Design
So first there was like a screening round and then I had an online interview that was about data structures and algorithms. Then I went onsite for another technical interview where they asked about some AI concepts and also an LRU cache design. After that, I had a round with the VP, and they asked a leetcode question about finding the longest palindromic substring. They seemed to like me, but then a week later they told me they went with someone else.
Confirmed questions3 questions
- How would you split sentences with no spaces into meaningful words?
- Can you explain some AI concepts and design an LRU cache?
- Find the maximum length of a palindrome string.
PubMatic Software Engineer Interview Questions
Quoted word for word from PubMatic interview reports.
“Given a node to be removed from a linked list, remove it without being given the head of the list.”
Read reports →“Given a decoded word where letters a through z correspond to numbers 1 through 26, count the frequency of each letter. For instance, '2a' implies two 'a's. The output should be an array of 26 integers, where the first element represents the count of 'a', the second 'b', and so forth up to 'z'.”
Read reports →“Regarding free(), how does it determine the size of the block to be freed when malloc only provides the starting address?”
Read reports →“For a binary tree composed of strings, can you return the stream of strings as char* such that reversing the parse yields the original tree?”
Read reports →“How would you convert a linked list from [l1->l2->l3->...->ln-1->ln ] to [l1->ln->l2->ln-1->...] in O(n) time and O(1) space?”
Read report →“Suppose you have an array of size m (where m is less than n) containing numbers from 1 to n, with n-m numbers missing. For example, if n=10 and the array is [1,6,4,8,7], what are the missing numbers?”
Read report →“For a crossword puzzle, if given a dictionary and an mXn grid, how would you determine the number of valid words that can be formed?”
Read report →“Can you sort a single linked list where each node also contains a sub-list?”
Read report →“Considering two dice and the numbers 0-9, how would you assign numbers to each side of the dice so that they can represent all the days of all the months?”
Read report →Formats, difficulty and experience
Across all 61 PubMatic interview reports.