Clinical Research Scientist

Apple

Given an integer n, return the count of all numbers with unique digits, x, where 0 <= x < 10^n. For example: Input: n = 2 Output: 91 Explanation: The answer should be the total numbers in the range of 0 <= x < 100, excluding 11,22,33,44,55,66,77,88,99 Input: n = 0 Output: 1

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

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.