Technology PPA Engineer

Apple

Given a string expression of numbers and operators, return all possible results from computing all the different possible ways to group numbers and operators. You may return the answer in any order. The test cases are generated such that the output values fit in a 32-bit integer and the number of different results does not exceed 104. For example: If the input is expression = 2-1-1 The expected output is [0,2] Because: ((2-1)-1) = 0 (2-(1-1)) = 2 If the input is expression = 23-45 The expected output is [-34,-14,-10,-10,10] Because: (2(3-(45))) = -34 ((23)-(45)) = -14 ((2(3-4))5) = -10 (2((3-4)5)) = -10 (((23)-4)5) = 10 Constraints: 1 <= expression.length <= 20 expression consists of digits and the operator '+', '-', and '*'. All the integer values in the input expression are in the range [0, 99]. The integer values in the input expression do not have a leading '-' or '+' denoting the sign.

Apple

Let's explore the concept of FIFO (First-In, First-Out) depth in the context of data structures. What is FIFO depth, and why is it important to consider when designing and implementing a FIFO queue?** Explain how FIFO depth affects performance (latency and throughput), resource utilization (memory), and error conditions (overflow and underflow).** Can you provide a detailed example of a real-world scenario where FIFO depth is a critical parameter, like in a communication system or hardware design? For instance, if you are designing a system to process network packets, what factors would influence your choice of FIFO depth for the packet buffer? How does the arrival rate of packets, the processing time for each packet, and the acceptable packet loss rate play a role in determining the appropriate FIFO depth?** Also, discuss different strategies for managing FIFO depth dynamically based on system load and resource availability. How can adaptive FIFO depth control improve overall system performance and robustness?** What are some techniques to estimate the required FIFO depth analytically or through simulation?**

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.