Q.1: Count the number of black shapes in a 2-D bit map containing 0s and 1s (Bar-raiser)
Q.2: Design a network of vending machines where customers can collected their food items ordered on Amazon.com. Follow-up was to extend this system to enable suppliers to stock the vending machines. Focus was placed on high-level design, scalability, and details of the back-end system design. Also, each design decision had to be justified.
Q3: Design a queue using an array. Queue should be dynamically resizable.
Q4: Design a game-controller to administer two games: Tic-Tac-Toe (traditional 3x3 board and a more generic mxn board) and Connect-4 (a generic mxn board). Focus was more on object-oriented design and the use of appropriate design patterns. The interviewer wanted to see various classes and their relationships, and some basic APIs to manage these games.
Each of these 4 questions were preceded by behavioral questions on Amazon’s Leadership Principles https://www.amazon.jobs/principles. Be sure to prepare them well.