Research Scientist L5, Algorithms Engineering

Netflix

You are given the definition of a binary tree node: class Node: def init(self, val=0, left=None, right=None): self.val = val self.left = left self.right = right Write a function is_bst(root) that takes the root of a binary tree as input and returns True if the tree is a valid Binary Search Tree (BST), and False otherwise. Definition of a BST: The left subtree of a node contains only nodes with keys less than the node's key. The right subtree of a node contains only nodes with keys greater than the node's key. Both the left and right subtrees must also be binary search trees. Example 1: Input: root = [2,1,3] Output: true 2 / 1 3 Example 2: Input: root = [5,1,4,null,null,3,6] Output: false 5 / 1 4 / 3 6 Explanation: The root node's value is 5 but its right child's value is 4. Constraints: The number of nodes in the tree is in the range [1, 10000]. -10000 <= Node.val <= 10000 Your solution should handle edge cases such as an empty tree or a tree with only one node.

Netflix

Let's design a tool to evaluate GitHub repositories based on metrics like stars and forks. Functionality:** The tool should: Fetch data from the GitHub API (stars, forks, open issues, contributors, etc.) for a given repository. Calculate a popularity score based on a weighted combination of these metrics. For example, stars might have a higher weight than open issues. Allow users to compare multiple repositories side-by-side. Present the data in a clear and visual way (charts, graphs, tables). Allow users to customize the weights used in the popularity score calculation. Handle API rate limiting gracefully (e.g., caching, authentication). Include features for trending topics/repositories. Example:** A user wants to compare the popularity of facebook/react versus angular/angular. They should be able to enter these repositories into the tool and see a comparison table showing the number of stars, forks, open issues, and the calculated popularity score for each. The user should also be able to adjust the weight given to stars in the popularity score to see how it affects the overall ranking. Consider additional features like displaying the rate of growth over the last month/year. What are the key components, architecture, and considerations for building such a tool, and what technologies would you choose and why?

Netflix

Tell me about a time you faced a significant ethical dilemma. What made it difficult, and what was the outcome? Describe the situation in detail, explaining the context and the stakeholders involved. Explain your thought process as you evaluated the ethical considerations. What alternatives did you consider, and why did you choose the path you did? What was the result of your actions, and what did you learn from the experience? For example, perhaps you discovered a colleague was misrepresenting their work or claiming credit for someone else's contributions. Or maybe you identified a potential safety issue with a product or service that your company was preparing to launch. Discuss how you navigated the situation, ensuring that your actions aligned with your personal and professional values, while also considering the potential impact on your team, the company, and other stakeholders. Explain how you communicated your concerns and the steps you took to reach a resolution, reflecting on whether you would approach the situation differently in the future.