Paytm Interview Experience | Set 8 (Hiring Drive for Backend Engineer)

Paytm Hiring Drive for Backend Engineer. The selection process was completed on the same day.

• Round 1 ( Written ): It was a technical written round with 20 questions out of which 2 were coding questions. Rest 18 was objective type mainly C, SQL, and Algo.
  • Write code to create a mirror image of a tree.
  • Given an array of arrival and departure times of guests, find a minimum no of rooms required to accommodate guests at any point of time.
• Round 2 :
  1. WAP to search a number in a row-wise – column-wise sorted matrix.
  2. Flatten a linked list.
  3. Discussions around Binary Search and Ternary Search.
  4. Discussed objective questions of a written round.
• Round 3 :
  1. How will you store a series of mobile nos in memory efficiently (less space). e.g mobile nos like 999900001,999900003,999900005,999910006,999910007 … are there. DS should be designed such that retrieval is not inefficient.
  2. Stream of Access logs is given to you with user id, page id, and date. Design Data structure to find n recent unique visitors and pages they visited.
  3. The current company projects discussions.

I thank GFG a lot for helping me in my preparation, finally, I was selected ?