Software Engineer, Enterprise Systems

Apple

Given two integer arrays inorder and postorder where inorder is the inorder traversal of a binary tree and postorder is the postorder traversal of the same tree, construct and return the binary tree. For example: Example 1: inorder = [9,3,15,20,7], postorder = [9,15,7,20,3] Expected Output: [3,9,20,null,null,15,7] Example 2: inorder = [-1], postorder = [-1] Expected Output: [-1] 1 <= inorder.length <= 3000 postorder.length == inorder.length -3000 <= inorder[i], postorder[i] <= 3000 inorder and postorder consist of unique values. Each value of postorder also appears in inorder. inorder is guaranteed to be the inorder traversal of the tree. postorder is guaranteed to be the postorder traversal of the tree.

Apple

Let's discuss platform architecture. Imagine you are tasked with designing a platform for a rapidly growing social media company. This platform needs to handle millions of users, support various media types (images, videos, text), and provide real-time updates. Consider the following: Scalability: How would you design the architecture to ensure it can handle increasing user traffic and data volume? Discuss specific technologies and strategies (e.g., load balancing, caching, sharding). Reliability: What measures would you take to ensure the platform remains available and fault-tolerant? Consider redundancy, monitoring, and disaster recovery. Performance: How would you optimize the platform for speed and responsiveness? Address concerns like database performance, content delivery, and API design. Security: What security considerations would you prioritize to protect user data and prevent attacks? Think about authentication, authorization, encryption, and vulnerability management. Cost: How would you balance performance, scalability, and reliability with cost-effectiveness? Discuss trade-offs and potential cost optimization strategies. Provide a high-level overview of your proposed architecture, including key components, technologies, and design principles. Explain your reasoning behind each choice and how it contributes to the overall goals of the platform. For example, would you choose a microservices architecture or a monolithic architecture? What type of database would you use and why? How would you handle real-time updates and notifications? What CDNs would you use?

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.