Software Dev Engineer, Business Data Technologies

Amazon

Given a graph represented as an adjacency list, write a function to perform a Depth-First Search (DFS) traversal starting from a given node. The function should print each visited node. Also, provide an example graph and demonstrate how your function would traverse it. Explain the time and space complexity of your solution. For example, consider the following graph: { 0: [1, 2], 1: [2], 2: [0, 3], 3: [3] } If we start the DFS traversal from node 2, the expected output would be: 2, 0, 1, 3 (or another valid DFS traversal order). Your function should: Take the graph (adjacency list) and a starting node as input. Implement DFS traversal. Print each visited node. Correctly handle cycles to avoid infinite loops. Analyze and state the time and space complexity of your implementation.

Amazon

Elevator System Design Design an elevator system for a 20-story building. Consider the following: Number of Elevators: How many elevators would you recommend, and why? Elevator Capacity: What should be the capacity (in terms of weight and number of people) of each elevator? Algorithm for Request Handling: Describe an algorithm for efficiently handling elevator requests, considering factors like minimizing wait times and energy consumption. Example: Should the elevator always go to the closest floor first, or should it consider the direction of travel? Edge Cases and Error Handling: How would you handle edge cases such as: Elevator malfunction? Power outage? Overweight elevator? Simultaneous requests from multiple floors? Optimization: How can you optimize the system for peak hours (e.g., morning rush hour, lunch break)? Consider strategies like: Designating specific elevators for up/down travel during peak times. Implementing a learning system that adapts to usage patterns. User Interface: Describe the user interface (both inside the elevator and on each floor) and how it provides feedback to users. Scalability: How would the design change for a 50-story or 100-story building? What are the limitations of your current design? Explain your design choices and justify them with appropriate reasoning. Focus on creating a robust, efficient, and user-friendly elevator system.

Amazon

Tell me about a time you exemplified one of Amazon's leadership principles. For example, consider the 'Customer Obsession' principle. Can you describe a situation where you went above and beyond to meet a customer's needs, even when it was challenging or required you to think outside the box? What specific actions did you take, and what was the outcome? Alternatively, let's explore the 'Bias for Action' principle. Share an instance where you had to make a quick decision with limited information. What was the situation, what factors did you consider, and how did you mitigate the risks associated with acting swiftly? Or perhaps you can elaborate on a time you demonstrated 'Ownership.' Describe a project or task where you took full responsibility for the outcome, even when things didn't go as planned. How did you handle the setbacks, and what did you learn from the experience? Another good principle to discuss could be 'Invent and Simplify.' Tell me about a time you created an innovative solution to a complex problem, while keeping it simple and easy to use. What was the problem, what was your solution, and how did you ensure its simplicity? Finally, tell me about a time where you had to 'Learn and Be Curious'.