Technical Program Manager (L6), Privacy & Data Protection Engineering

Netflix

Design and implement an LRU (Least Recently Used) cache. Your cache should support the following operations: get(key) - Gets the value (will always be positive) of the key if the key exists in the cache, otherwise returns -1. put(key, value) - Sets or inserts the value if the key is not already present. When the cache reaches its capacity, it should invalidate the least recently used item before inserting a new item. For the purpose of this question, when a new key is inserted, regard it as most recently used. The cache is initialized with a positive capacity. Example: LRUCache cache = new LRUCache(2); // capacity is 2 cache.put(1, 1); cache.put(2, 2); cache.get(1); // returns 1 cache.put(3, 3); // evicts key 2 cache.get(2); // returns -1 (not found) cache.put(4, 4); // evicts key 1 cache.get(1); // returns -1 (not found) cache.get(3); // returns 3 cache.get(4); // returns 4 Follow up: Could you do both operations in O(1) time complexity?

Netflix

Let's design an A/B test to re-engage inactive users of a mobile fitness app. Assume that users are considered inactive if they haven't used the app for 30 days. Our goal is to increase the number of users who return and actively use the app. Consider the following when designing your A/B test: Control Group: This group receives no intervention. We'll use this as our baseline to measure against. Treatment Group A: Push Notification with Personalized Workout Recommendations: Users in this group receive a push notification that includes workout recommendations tailored to their past activity and fitness goals (e.g., Ready for your next challenge? Try this 30-minute HIIT workout based on your past activity!). Treatment Group B: In-App Discount on Premium Features: Users in this group receive a notification when they open the app offering a discounted rate on the app's premium features, such as personalized training plans or access to exclusive content (e.g., Welcome back! Enjoy 50% off a premium training plan this week only!). For this A/B test design, specify: The hypothesis for each treatment group. The target metric(s) you would track to measure success, and how you would measure them. The segmentation you might consider when analyzing results (e.g. by workout type, fitness level, demographics). The duration of the A/B test and the sample size needed for statistical significance. Explain your reasoning. The potential risks and how you would mitigate them.

Netflix

Tell me about a time you went above and beyond what was expected of you.