Systems Development Engineer, Enterprise Engineering

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 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

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.