Software Engineering Manager

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 talk about semaphores. Could you please explain what semaphores are, and how they are used in operating systems or concurrent programming? Provide examples of situations where semaphores are useful for controlling access to shared resources. Explain the difference between binary and counting semaphores. Furthermore, can you discuss potential problems that can arise when using semaphores, such as deadlocks or starvation, and how these problems can be addressed? For instance, consider a scenario where multiple threads need to access a database connection pool. How can semaphores be employed to manage access to the limited number of connections in the pool, preventing overuse and ensuring fair allocation among threads?

Apple

Let's discuss your approach to debugging malfunctions. Imagine you are on call for a critical e-commerce platform, and users start reporting that they are unable to complete their purchases. The error logs show a vague Transaction Failed message with no clear indication of the root cause. The customer service team is overwhelmed with complaints, and the business is losing revenue every minute the issue persists. Describe your initial steps in diagnosing the problem.** What tools or techniques would you use to gather more information? Would you focus on the front-end, back-end, or both? How would you prioritize your debugging efforts?** Would you start by examining the most recent code changes, monitoring server resources, or checking database connections? Explain your strategy for isolating the fault.** What methods would you employ to narrow down the potential causes of the malfunction, such as bisecting the code, using debugging tools, or performing hypothesis testing? Outline your approach to resolving the issue.** Once you have identified the root cause, what steps would you take to fix it quickly and effectively? How would you ensure that your fix does not introduce new problems? Discuss how you would prevent similar malfunctions from occurring in the future.** What proactive measures would you implement to improve the platform's reliability and resilience, such as adding better logging, implementing automated testing, or improving monitoring? Walk me through your thought process and provide specific examples of how you would tackle each step of the debugging process. I'm interested in hearing about your experience with similar situations and how you have successfully resolved them in the past.