Amazon Interview Experience SDE-2 (3 Years Experienced)

I was interviewed at Amazon Bengaluru for SDE 2 role.

Round 1 (Online Test, Hackerrank): Doesn't Remember the questions. But one was easy and the other was the stack-based medium-level question.

Round 2 (Video Call, Technical): Started with a basic introduction and then two DSA questions.

• https://www.geeksforgeeks.org/dsa/count-number-ways-tile-floor-size-n-x-m-using-1-x-m-size-tiles/
• https://www.geeksforgeeks.org/dsa/find-two-missing-numbers-set-2-xor-based-solution/
  

Round 3 (Video Call, Managerial & HLD): Started with a basic introduction asking about some of the projects I did.

Behavioral Question: Tell me about a time you failed at work. What did you learn from it?

HLD Question: Designing a URL shortener service

Round 4 (Video Call, Technical, LLD):

Started with a basic introduction asking about some of the projects I did.

Tell me about the most challenging project you ever worked on

LLD Question: Design Twitter Apis, basic database design and how will you load user timeline optimally.

Round 5 (Video Call, Bar Raiser): This round was completely behavioral. Inclusive of questions about work that I have done.

• Why Amazon?
• Tell me about a challenge you faced. What was your role & the outcome?
• Tell me about a time when you went over and above your job responsibility to help the company

Technical Question:

• Given a complete binary tree, perform the following spiral traversal of the tree
• print left most nodes on each level from top to bottom
• print all nodes on the bottom-most level from left to right
• print right-most nodes on each level from bottom to top
• every node is to be visited only once, perform this iteration until the whole tree is traversed

 1
 2 3
 4 5 6 7
 8 9 10 ................................. 15
 16 17 ............................................. 31
32 33 ................... 62 63

Solved this using bfs and map of the deque.

Interviewer gave me suggestion to solve this using dequq<deque> instead of map<int, dqueue> as removing element in dequq<deque> takes O(1) while map<int, dqueue> in worst case took O(logn).