Hardware Reliability Engineer - Mac System Reliability

Apple

You are given a 0-indexed array of positive integers nums. A subarray of nums is called incremovable if nums becomes strictly increasing on removing the subarray. For example, the subarray [3, 4] is an incremovable subarray of [5, 3, 4, 6, 7] because removing this subarray changes the array [5, 3, 4, 6, 7] to [5, 6, 7] which is strictly increasing. Return the total number of *incremovable* subarrays of nums. Note that an empty array is considered strictly increasing. A subarray is a contiguous non-empty sequence of elements within an array. Example 1: Input: nums = [1,2,3,4] Output: 10 Explanation: The 10 incremovable subarrays are: [1], [2], [3], [4], [1,2], [2,3], [3,4], [1,2,3], [2,3,4], and [1,2,3,4], because on removing any one of these subarrays nums becomes strictly increasing. Note that you cannot select an empty subarray. Example 2: Input: nums = [6,5,7,8] Output: 7 Explanation: The 7 incremovable subarrays are: [5], [6], [5,7], [6,5], [5,7,8], [6,5,7] and [6,5,7,8]. It can be shown that there are only 7 incremovable subarrays in nums. Example 3: Input: nums = [8,7,6,6] Output: 3 Explanation: The 3 incremovable subarrays are: [8,7,6], [7,6,6], and [8,7,6,6]. Note that [8,7] is not an incremovable subarray because after removing [8,7] nums becomes [6,6], which is sorted in ascending order but not strictly increasing.

Apple

Let's design a system for URL shortening, like TinyURL. Assume a large-scale service. Please consider the following aspects in your design: Functional Requirements: The system should generate shorter URLs (a.k.a. short links) given longer URLs. Users should be able to navigate to the original URL by entering the short link in their browser. The system should be highly available. Non-Functional Requirements: The system should have low latency for both URL shortening and redirection. Short links should be relatively short (e.g., 6-8 characters). The system should be able to handle a large number of URL shortening and redirection requests. Capacity Estimation: Assume 100 million URLs are shortened per day. Assume 1 billion URL redirections per day. Estimate storage requirements for 5 years. Design Considerations: How would you generate unique short links? What data structures and databases would you use to store the URL mappings? How would you handle collisions when generating short links? How would you optimize for low latency redirection? How would you scale the system to handle the expected traffic? Walk me through your design, explaining your choices and the trade-offs you considered. Provide diagrams where necessary to illustrate the architecture.

Apple

Let's explore your resume and then dive into a coding question. First, regarding your resume: Could you walk me through a project that you are particularly proud of? Describe your role, the challenges you faced, and the solutions you implemented. Be specific about the technologies you used and the impact your contributions had on the project's outcome. Tell me about a time you had to work with a technology or framework that you were unfamiliar with. How did you approach learning it, and how did you apply it to the project at hand? What resources did you find most helpful, and what challenges did you encounter during the learning process? Describe a situation where you had to make a trade-off between different approaches or technologies. What factors did you consider when making your decision, and how did you evaluate the potential consequences of each option? Can you provide a specific example of such a trade-off? Now, for the coding question: Given a list of integers, write a function to find the contiguous sub-array with the largest sum. For example, if the input is [-2, 1, -3, 4, -1, 2, 1, -5, 4], the output should be [4, -1, 2, 1], with a sum of 6. Explain your approach, and provide a working implementation of the function in your preferred programming language. Consider edge cases such as an empty input list or a list with only negative numbers. What is the time complexity of your solution? Can you optimize it further?