Software Developer 2 (Performance Test/Automation Engineer)

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 URL shortening service like bit.ly. Consider the following: Functional Requirements: The service should accept a long URL and generate a unique short URL. Users should be able to access the original URL by visiting the shortened URL. The service should track click statistics for each shortened URL. Non-Functional Requirements: The service should be highly available and scalable to handle a large number of URL shortening and redirection requests. Shortened URLs should be generated quickly. The system should be fault-tolerant. Considerations: How would you handle URL collisions (when the same short URL is generated for different long URLs)? How would you design the data storage? How would you optimize the system for read-heavy traffic (redirections)? How would you implement analytics and track clicks? Explain the architectural components, data model, algorithms, and scaling strategies you would use to build such a system. Provide specific examples for URL encoding and decoding. For example, how would you encode https://www.example.com/very/long/url/path into something like bit.ly/xyz123?

Oracle

Let's discuss your strengths and weaknesses. Could you provide specific examples that highlight both your key strengths and areas where you are actively working to improve? Think about situations where your strengths significantly contributed to a positive outcome, and conversely, instances where your weaknesses presented a challenge. For instance, perhaps you excel at quickly learning new technologies, as demonstrated by your successful implementation of a novel machine learning algorithm for a recent project, resulting in a 15% performance improvement. On the other hand, you might find public speaking challenging, and you are addressing this by joining a Toastmasters club and practicing presentations regularly. Providing concrete examples like these will give me a better understanding of your capabilities and your commitment to continuous self-improvement.