Software Engineer L4/L5, Model Serving Systems, Machine Learning Platform

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

Let's delve into your past projects and experiences. I am interested in understanding how you approach problem-solving in real-world scenarios. Could you walk me through a particularly challenging project you've worked on, outlining the initial problem, the steps you took to address it, and the final outcome? What obstacles did you encounter, and how did you overcome them? Furthermore, what specific technologies or methodologies did you employ, and why were they chosen? For example, perhaps you worked on a project to optimize a database query that was causing performance bottlenecks. What steps did you take to identify the root cause of the bottleneck? Did you use any specific profiling tools or techniques? How did you determine the best approach to optimize the query, and what were the trade-offs involved? What was the measurable impact of your optimization efforts on the overall system performance? Alternatively, consider a project where you were tasked with migrating a legacy application to a new platform. What were the key challenges involved in this migration? How did you ensure data integrity and minimal downtime during the transition? What strategies did you use to manage the complexities of the migration process, and how did you collaborate with other team members to achieve a successful outcome? Finally, reflect on a time when you had to learn a new technology or skill quickly to contribute to a project. What strategies did you employ to accelerate your learning process? How did you apply your newfound knowledge to solve real-world problems within the project, and what lessons did you learn from this experience?