Embedded Software Engineering Manager - Cellular Modem Software

Apple

Given an integer array nums where every element appears three times except for one, which appears exactly once. Find the single element and return it. You must implement a solution with a linear runtime complexity and use only constant extra space. For example, if the input is nums = [2,2,3,2], the output should be 3. Another example, if the input is nums = [0,1,0,1,0,1,99], the output should be 99. How do you solve this problem, considering edge cases like empty input, presence of zero, and negative numbers?

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 the concept of feedback amplifiers in the context of software development teams. Imagine you are leading a team working on a critical feature for a new mobile application. Communication bottlenecks and misunderstandings are starting to impact the team's velocity and morale. As a senior engineer, you recognize the need to amplify feedback loops to improve team performance. Describe what a feedback amplifier is and how it works in practice.** Provide concrete examples of how you would implement feedback amplifiers within your team. Consider different types of feedback, such as code reviews, sprint retrospectives, and individual performance reviews. Explain the benefits of using feedback amplifiers.** How can they improve code quality, reduce bugs, and increase team collaboration? Quantify the potential impact using hypothetical scenarios or past experiences. For instance, how might more frequent code reviews, coupled with automated static analysis, lead to a measurable reduction in the number of bugs discovered in production? Discuss the potential challenges and pitfalls of implementing feedback amplifiers.** What steps would you take to mitigate these risks? Think about issues like information overload, negative feedback bias, and the time investment required to implement and maintain effective feedback loops. How would you ensure that the feedback process remains constructive, fair, and actionable for all team members? Elaborate on your answer by considering specific tools or techniques you have used in the past to amplify feedback, such as using dashboards to visualize key performance indicators, conducting regular pulse surveys to gauge team sentiment, or establishing a system for tracking and resolving action items from retrospective meetings. Also, discuss how you would tailor your approach based on the size and structure of the team, as well as the specific project goals and constraints.