Storage Validation Engineer

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

Tell me about the most difficult project you've ever worked on and how you managed to deliver. To provide context, please consider these aspects: What were the specific challenges? For example, was it a tight deadline, limited resources, a novel technology, ambiguous requirements, or conflicting stakeholder expectations? Elaborate on the nature and magnitude of these challenges. What role did you play? Were you leading the project, a core contributor, or in a support role? Describe your responsibilities and level of autonomy. What specific actions did you take to overcome these challenges? Did you implement any specific strategies, tools, or methodologies? Did you have to make any difficult decisions or trade-offs? Provide concrete examples of your problem-solving approach, technical skills, and leadership abilities. How did you collaborate with your team and stakeholders? Describe how you communicated progress, resolved conflicts, and ensured alignment among team members and stakeholders. Did you have to manage any difficult personalities or navigate any political sensitivities? What were the results of your efforts? Did you successfully deliver the project? Did you meet or exceed expectations? What were the key lessons learned from this experience? Quantify your accomplishments whenever possible (e.g., reduced costs by X%, improved efficiency by Y%). For instance, perhaps you spearheaded the development of a new machine learning model with a very aggressive timeline while dealing with constantly shifting requirements from the business team and a lack of readily available training data. Or maybe you were tasked with migrating a legacy system to a modern cloud-based architecture with limited budget and a team with varying levels of expertise. Or consider a situation where you were responsible for launching a new product feature under immense pressure from senior management, requiring you to make tough calls on scope and prioritize ruthlessly. Share your story, highlighting the obstacles you faced and how you successfully navigated them.