PayU Interview Experience | 2+ Years Experienced

 I received an email from a recruiter to schedule the virtual interviews. The recruiter informed me that each round would be an elimination round, meaning that if I did not perform well, they would not proceed to the next round. Three rounds were planned in total. [2 technical + 1 (Technical + Managerial)].

All the rounds were on the same day. 

Round 1: An SDE-2 intercepted it. His communication and technical abilities were excellent.

• Find the Missing Number
• Depth Sum or Nested List Weight Sum 
  Sample Input: [1 [4 [6]]] Output: 27.   
  Explanation: 1 * 1 + 4 * 2 + 6 * 3 = 27( Number in the red color are the level in the nested list. )
• Derive time and space complexity for both the problems

Round 2:

• The interviewer asked me to introduce myself and explain my projects.
• Asked me to write functions with Decorators with detailed explanation.
• Explain Restful APIs.
• Difference between primary key and Unique key in SQL.
• Given an array, print the Next Greater Element (NGE) for every element. 
• Given an array of random numbers, Push all the zero’s of a given array to the end of the array.
• Discussion on Indexing in SQL.

Round 3: 

• The interviewer asked me to introduce myself,
• Asked me to explain and design tables and how data is flowing into the tables in my project.
• Why use Python for web development and how python is used in Instagram along with different databases.
• How multiprocessing in Instagram works, event-driven programming in Python.
• What is AWS lambda and how it is useful?
• Detailed discussion about current role and responsibilities.

Round 4: 

• This was the final HR round. I introduced myself and she asked why PayU. That’s all.