Paytm visited our campus on 24th August for Software Engineer Role.
Round 1: Coding Round
This one happened for 70 mins where we were given 3 coding questions to solve.
- https://www.geeksforgeeks.org/check-whether-number-circular-prime-not/amp/
- I don’t remember the exact question but it is the variation of the standard problem: Min Coast Path.
- https://www.geeksforgeeks.org/permute-the-elements-of-an-array-following-given-order/amp/
After this, list of all the shortlisted students came in which total of 44 students was shortlisted and Interviews were scheduled on 4th September but due to an internal event at Paytm the interviews were postponed and rescheduled for the 16th of September.
Round 2: Technical Round
Time: 1 hour
- It started with my introduction and then he moved on to the questions:
- Did he ask about my favorite Data Structure? I answered Trees then he asked if I know graphs I told him, yes but it certainly is not my favorite. Then he said let’s start with least favorite then.
- He asked if I know about bridges in graphs and asked me to explain the same. He told me to derive an approach to find bridges efficiently.
- When to use BFS and when to use DFS?
- Then he asked how are unordered_map and map implemented?
- What is a heap? How is it stored?
- What is BST? Can we use BST instead of heaps? If yes why if no why?
- What is priority_queue? Does removing the top element from the queue result in heap still following the heap property? What’s its time complexity?
- He asked a coding question which was a twisted version of the following GFG ques. https://www.geeksforgeeks.org/find-duplicates-in-on-time-and-constant-extra-space/amp/
- First I told him the approach using maps and then he asked for O(1) space then I told him that.
- Then he asked what is LRU Cache and how would I be implementing it. He just asked for the approach and no code was needed. https://www.geeksforgeeks.org/lru-cache-implementation/amp/
- Then he asked about sorting and searching algorithms I know.
- Then he asked which sorting algorithm is best and if it depends on the situation then what is preferred when?
- He asked about the Insertion sort algorithm I honestly told him I don’t remember it.
- He said he is finished with the questions and if I have any questions for him.
Round 3: Technical Round
Time: 45 min
Started with my introduction and then he moved on to questions:
- He asked about the languages I know. I told him I do my coding in C++.
- He then asked about interfaces. I told him that interfaces are in java and as per my knowledge it’s quite similar to abstract classes in C++. He asked me to explain the same.
- Then he asked about static members what are those and why is it used?
- Given me different scenarios and asked where static members are preferred over normal members.
- Then he moved on to the DSA questions.
- The first one was https://www.geeksforgeeks.org/edit-distance-dp-5/amp/
- I explained my approach using recursion and then he asked to code it.
- For the second one, he just asked about the approach I would follow. It was a slight variation of-https://leetcode.com/problems/number-of-islands/
- Then he gave me two tables and asked SQL queries on them. I first wrote the query using subquery but he asked me to try with another approach and then I used joins.
- Then he was asked to describe all the types of Joins.
- He told that he is done with the question and if I have any questions for him.
Verdict: Selected, A total of 4 students were given the offer including me.
Tips:
- Be Calm and interact with the interviewer as much as possible.
- I would like to Thank GeeksforGeeks for such wonderful content and detailed coverage of all topics.
Thank you and All the best.