Principal Software Engineer - Distributed Systems

Oracle

Let's explore binary search trees. Consider that you are given a stream of numerical data. Your task is to design and implement a self-balancing binary search tree (BST) data structure that efficiently supports the following operations: Insertion: Insert a new number into the BST while maintaining its self-balancing property. The balancing mechanism should ensure that the height of the tree remains logarithmic in the number of nodes. Implement the insertion logic and explain the balancing technique used (e.g., AVL trees, Red-Black trees). Search: Given a number, determine if it exists in the BST. Implement an efficient search algorithm that leverages the BST property to locate the number or confirm its absence. Deletion: Remove a number from the BST while maintaining its self-balancing property. Handle different deletion scenarios, such as deleting a leaf node, a node with one child, and a node with two children. Describe how the balancing is preserved after deletion. Range Query: Given a range (min, max), return all numbers within the BST that fall within this range, in sorted order. Optimize the range query to avoid traversing unnecessary parts of the tree. For example, if the stream of numbers is [10, 5, 15, 3, 7, 12, 18], the BST should dynamically adapt to maintain balance as each number is inserted. Demonstrate how your implementation handles operations like inserting 6, deleting 10, and performing a range query for numbers between 6 and 16. Discuss the time complexity of each operation in terms of the number of nodes in the tree (n) and the height of the tree (h). Pay close attention to edge cases and error handling in your implementation.

Oracle

Let's design a system for deleting all user data in a large-scale application. Consider the following requirements: Compliance: The system must adhere to data privacy regulations (e.g., GDPR, CCPA) regarding the right to be forgotten. This means all personal data must be permanently and irrevocably deleted. Data Scope: User data is distributed across various databases (e.g., relational, NoSQL), object storage, and potentially third-party services. Examples include: User profiles in a relational database (name, email, address). User-generated content (photos, videos) in object storage. User activity logs in a NoSQL database. User data cached in a Redis cluster. User accounts on integrated third-party services (e.g., payment processors, social media platforms). Performance: The deletion process should be efficient and not significantly impact the performance of other system operations. Consider the impact on databases and other services during peak hours. Consistency: The system must ensure data consistency. For example, if a user has dependencies on other data (e.g., a user is an administrator of a group), these dependencies must be handled correctly (e.g., reassigning ownership, deleting dependent data). Auditability: All deletion requests and actions must be logged for auditing and compliance purposes. The logs should record who requested the deletion, when it was requested, what data was deleted, and the outcome of the deletion process. Error Handling: The system should gracefully handle errors and retries. If a deletion fails in one component, it should be retried or rolled back appropriately, and alerts should be generated. Scalability: The system must be able to handle a large number of deletion requests concurrently. Data Minimization: Before initiating the deletion process, verify if data minimization techniques can be applied instead of complete deletion, such as anonymization or pseudonymization, especially for datasets needed for analytical purposes. Given these requirements, how would you design a system to handle user data deletion requests? Discuss the architecture, components, data flow, and any trade-offs you would consider.

Oracle

Okay, let's imagine we're at a career fair, and you have about two minutes to introduce yourself to a recruiter. Keeping that timeframe in mind, could you provide a concise overview of your background, skills, and career aspirations? Think of it as your elevator pitch. For example, you might highlight your key accomplishments from previous roles, discuss your proficiency in specific programming languages or technologies relevant to the target position, and briefly touch upon your career goals and what you're hoping to achieve in your next role. What makes you a great candidate?