Amazon Interview Experience For Software Developer Intern

Amazon visited our campus around late September to hire for the role of Software Developer Intern. There were 3 rounds involved in the process.

• An online test
• Two technical interviews.

The online test was organized on Mettl Platform and consisted of the following parts :

• Debugging: Had to apply some changes to a given code snippet to make it logically and syntactically correct.
• Psychometric Test: Situational questions.
• Reasoning: Was relatively easier than you would usually find in other placement tests.
• Two coding questions : 
  1. Rewrite of Search in a matrix: https://www.w3wiki.net/search-in-row-wise-and-column-wise-sorted-matrix/
  2. Rewrite of Bridges in a graph: https://www.w3wiki.net/bridge-in-a-graph/

Technical Round 1:

• Started with the introduction.
• Then two coding questions were asked :
• Given the data of n buses in a bus station with their arrival and departure time, find the minimum number of platforms required so that none of the buses overlap: https://www.w3wiki.net/minimum-number-platforms-required-railwaybus-station/
• Gave an O(nlogn) solution by sorting all the timings.
• Given a binary matrix, find the number of shapes and their parameter (length) present in the matrix. A shape is a sequence of consecutive ones, and we can move in all eight directions: https://www.w3wiki.net/find-number-of-islands/
• Solved using BFS.
• Discussion on time and space complexities of each problem.

Technical Round 2 :

• Again started with the introduction and simple questions related to one of my projects.
• Then 2 coding questions :
• Given the prices of n stocks find the maximum profit that can be made by doing at most k transactions: https://www.w3wiki.net/maximum-profit-by-buying-and-selling-a-share-at-most-k-times/
• First I gave an O(n3) DP solution, then optimized it to O(n2).
• Given the heights of walls arranged from left to right find the volume of water that will be trapped between the walls: https://www.w3wiki.net/trapping-rain-water/
• Gave an O(n) solution using the maximum wall to right and left for each wall.
• Discussion on time and space complexities for each problem.

 After about a week, I got the news through my college that I have been selected and given an internship offer. A total of 4 students got selected.