Systems Development Eng (AWS Generative AI & ML Servers), AWS Hardware Engineering Accelerators

Amazon

Given a binary tree, find the lowest common ancestor (LCA) of two given nodes in the tree. According to the definition of LCA on Wikipedia: “The lowest common ancestor is defined between two nodes p and q as the lowest node in T that has both p and q as descendants (where we allow a node to be a descendant of itself). For example: If the tree is [3,5,1,6,2,0,8,null,null,7,4], p = 5, q = 1, then the expected output is 3, because the LCA of nodes 5 and 1 is 3. If the tree is [3,5,1,6,2,0,8,null,null,7,4], p = 5, q = 4, then the expected output is 5, because the LCA of nodes 5 and 4 is 5, since a node can be a descendant of itself according to the LCA definition. If the tree is [1,2], p = 1, q = 2, then the expected output is 1. Consider these constraints: The number of nodes in the tree is in the range [2, 10^5]. -10^9 <= Node.val <= 10^9 All Node.val are unique. p != q p and q will exist in the tree.

Amazon

Let's design a Twitter-like service. Consider the following: Core Functionality: How would you implement the ability for users to post tweets, follow other users, and view a timeline of tweets from the users they follow? Data Model: What database schema would you use to store tweets, user information, and follower relationships? Consider scalability and efficiency for reads and writes. Scalability: How would you handle a large number of users and tweets? Discuss strategies for sharding, caching, and load balancing. Real-time Updates: How would you ensure that users see new tweets in their timeline in near real-time? Consider using technologies like WebSockets or Server-Sent Events. Search: How would you implement a search feature that allows users to find tweets containing specific keywords or hashtags? Think about indexing strategies and search algorithms. Rate Limiting: How would you prevent abuse and ensure fair usage of the service? Describe your approach to rate limiting API requests. Example Scenario: Imagine a user, Alice, follows 1,000 other users, including Bob. Bob posts a tweet. Explain how that tweet would propagate to Alice's timeline, considering potential performance bottlenecks. Technology Stack: What technologies (programming languages, frameworks, databases, etc.) would you choose and why?

Amazon

Tell me about yourself. To give you some guidance, please share information beyond just your resume. For example, what are you passionate about, what motivates you, and what are some of your long-term career goals? Think about some significant accomplishments you are proud of and how those experiences have shaped you. What makes you a unique candidate and a good fit for our company, beyond your technical skills? I'm looking for a comprehensive overview of who you are, both professionally and personally.