Software Development Engineer, S3 Replication

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

Why do you want to work at Amazon? To provide a comprehensive answer, consider the following aspects: Amazon's Mission and Values: How do Amazon's core values, such as customer obsession, innovation, bias for action, and ownership, resonate with your personal and professional values? Provide specific examples of how you've demonstrated similar values in your previous experiences. For instance, can you describe a situation where you went above and beyond to satisfy a customer, or when you took initiative to implement a novel solution to a challenging problem? Amazon's Culture of Innovation: Amazon is renowned for its innovative culture and willingness to experiment. How does this environment appeal to you? Are there any specific Amazon products, services, or initiatives that you find particularly inspiring or exciting? Perhaps you're impressed by Amazon Web Services (AWS), Amazon's foray into artificial intelligence with Alexa, or their advancements in logistics and delivery. Explain why these innovations capture your interest and how you believe you could contribute to future innovation at Amazon. Growth and Learning Opportunities: Amazon offers a wide range of opportunities for professional growth and development. What specific roles or career paths within Amazon are you interested in exploring, and why? Have you researched Amazon's internal training programs or mentorship opportunities? Discuss how you envision leveraging these resources to expand your skillset and advance your career within the company. For example, are you interested in moving into a leadership role, specializing in a particular technology, or working on a global scale? Your Skills and Experience: How do your skills and experience align with Amazon's needs and priorities? Identify specific projects or accomplishments from your past that demonstrate your ability to succeed in a fast-paced, demanding environment. Highlight any experience you have with technologies or methodologies that are relevant to Amazon's business, such as cloud computing, data analysis, machine learning, or agile development. Be prepared to discuss how your unique skills and experiences can contribute to Amazon's continued success. Can you quantify your accomplishments with metrics? Company Impact: What excites you about the potential to contribute to Amazon's impact on customers and the world? Consider how Amazon's products and services have transformed industries and improved people's lives. Are you drawn to the scale and scope of Amazon's operations, or the opportunity to work on projects that have a global reach? Express your enthusiasm for being part of a company that is constantly pushing boundaries and shaping the future.