Software Development Engineer, AWS FSx for Windows

Amazon

You are given a string moves of length n consisting only of characters 'L', 'R', and '_'. The string represents your movement on a number line starting from the origin 0. In the ith move, you can choose one of the following directions: move to the left if moves[i] = 'L' or moves[i] = '_' move to the right if moves[i] = 'R' or moves[i] = '_' Return the *distance from the origin* of the *furthest* point you can get to after n moves. Example 1: Input: moves = L_RL__R Output: 3 Explanation: The furthest point we can reach from the origin 0 is point -3 through the following sequence of moves LLRLLLR. Example 2: Input: moves = R__LL Output: 5 Explanation: The furthest point we can reach from the origin 0 is point -5 through the following sequence of moves LRLLLLL. Example 3: Input: moves = _ Output: 7 Explanation: The furthest point we can reach from the origin 0 is point 7 through the following sequence of moves RRRRRRR.

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

Describe a time when a plan did not go as expected.