Front-End Engineer II, Elastic Cloud Compute (EC2) Edge Networking

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

Let's explore scalability with a practical scenario. Imagine you're building a social media platform like Twitter, which needs to support millions of users who are constantly posting, liking, and re-sharing content. Consider these factors: Data Volume: Users generate terabytes of data daily. Read/Write Ratio: The platform experiences a high read-to-write ratio (many more reads than writes). Real-time Updates: Users expect to see new content and updates in real-time. Given these requirements, discuss the following: What are the key scalability challenges you anticipate? How would you approach scaling the platform's architecture to handle the increasing load, including database design, caching strategies, and load balancing? Describe specific technologies and techniques you might use to address each challenge. What are the trade-offs associated with different scaling approaches, and how would you evaluate the effectiveness of your scaling efforts?

Amazon

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