Paytm Interview Experience
Round 1:Online Coding Round First round was an online programming round with 3 questions.
- Merge two sorted(increasing order) Linked List such that the final Linked List is sorted in decreasing order.
- Given an array.A bad pair is a pair such that x%y=k and x occurs towards the left of y.Count all the subarrays which consist at least one bad pair.
Round 2: Face to Face interview:
- Firstly he started by discussing about my projects, both frontend and backend.
- Pattern matching:https://www.geeksforgeeks.org/searching-for-patterns-set-2-kmp-algorithm/
- Then he changed the question and told me to write another algo to find non overlapping patterns only:
- Example: If we want to search “abab” in a file then another pattern must not overlap with the previous “abab” in continuation.
- Then he asked questions on DBMS.
- He gave me 2 tables and asked simple queries on it.
- After that he asked that if we have millions of queries then how would you improve it.
- Then I told him about indexing which was followed by questions like which type of indexing will you use, on which attribute of the two table would you apply the indexing and why.
- Finally he told me to write the index query.
Round 3: Face to Face interview:
- Maximum distinct elements after removing k elements
- Then he asked me to draw a table that is not in 3NF form and convert it to 3NF form followed by questions like why you did that and what is the need for the conversion.
Round 4: Face to Face interview:
- Asked basic OOP’s concept and differences in usage in c++ and java.
- Questions on OS like: Scheduling algorithms, starvation, deadlock, semaphores etc.
- Then he asked me to draw the database of my Shopping Cart project showing its complete dependency which consisted of 5 tables followed by questions like why have you used the following attributes and the reason for choosing the following data types for the attributes metioned in the table.
- Finally he gave me Maths Question:
- There are 3 friends Sodh, Guruji and agrawal sitting on the vertices of an equilateral triangle.Sodh has 5 sticks, Guruji has 3 sticks and agrawal has none.So they kept all the 8 sticks at the centroid of the traingle and burned them all, each getting equal ammount of heat from the bonfire.In the morning agrawal realised about his nil contribution and gave Rs8 to Sodh.So how much money did Sodh need to give to Guruji.Ans:Rs1
Round 5: Face to Face interview:
- This round was completely based on project:
- He discussed about all my projects including AngularJS, JSP, API, Shopping Cart, CodeIgniter Framework and College Website Intership Project.
- He was very much interested in the API project and asked about its implementation and usage.
- Then he asked about security in APIs and sessions, so I told him about the encryption key used in sessions and the most commonly used md5 encryption for passwords.
- Finally he asked about my family background, so I told him that I belong to a business family followed by questions like business strategies etc.
- I also asked him about the worklife at paytm, technologies used and what I need to improve and learn for the near future.
HR Round: f2f:
- Family background, How were my previous interviews, Probability of getting selected, mistakes I made etc.