Received call from Recruiter through Naukri for Java Developer

Round 1

• I was allowed to choose any language for this DSA round, so I chose Python.
• Q1. Multiply 2 integers as strings https://leetcode.com/problems/multiply-strings/
• Q2. Populate right pointer of each node https://leetcode.com/problems/populating-next-right-pointers-in-each-node/description/
• For Q2 there was not enough time to code it so I explained the O(N) time and O(N) space solution. To which he said an O(LogN) space solution also exists.

Round 2

• LLD of Vending Machine
• Was asked to directly code the objects and methods (method implementation not required)
• I started with showing flow and identifying objects and methods in notepad first, then went to create then in IntelliJ.
• In my opinion, I did good, but the interviewer wanted design pattern to be used, and I hadnt used any.
• I explained we can use CoR in calculating the Cash amount.
• (Later I checked LLD of Vending Machine , everyone implements using some state Management Design pattern)
• I was not using that design pattern but managing the state in a different way.
• She asked how will I handle concurreny in this problem(or other problem in general), before I could answer she jumped to "How many design patterns you know about can you explain a few", I explained a few.
• She then said this vendingMachine class can be a singleton. (I find singletons pointless unless we have code to create an object at multiple places but we only need 1 instance)
• Overall Interviewer was pretty uninterested. She left the interview 2 times to get Coffee.
• Design rounds are supposed to be a discussion. Whenever I tried to discuss, she was like "code it first, else we might not get time at the end"
• Rejected at the end.

Compensation was 36LPA (no Joining Bonus or Stocks).