Strategic Risk Manager, Google Ads

Google

Given n pairs of parentheses, what is the total number of different, valid combinations of those parenthesis? For example: For n = 1, the only valid combination is (), so the answer is 1. For n = 2, the valid combinations are ()() and (()), so the answer is 2. For n = 3, the valid combinations are ((())), (()()), (())(), ()(()), and ()()(), so the answer is 5. Calculate the number of valid parenthesis combinations for a given n. Explain the formula or method used to arrive at the answer. What is the underlying mathematical concept at play here, and how does it ensure that we only count valid combinations, avoiding invalid ones such as )()(? Detail the relationship between this problem and Catalan numbers, and discuss how this relationship can be utilized to efficiently compute the number of valid combinations, even for relatively large values of n.

Google

Let's design a rate limiter for an API. The rate limiter should: Limit the number of requests a user can make to an API within a given time window. Support different rate limits for different users or API endpoints. For example, a free tier user might be limited to 10 requests per minute, while a premium user can make 100 requests per minute. Similarly, some API endpoints might have lower rate limits than others due to resource constraints. Be highly performant to avoid adding significant latency to API requests. Be scalable to handle a large number of users and API requests. Be reliable and prevent accidental overloads that could cause service disruptions. Describe the architecture, algorithms, and data structures you would use to implement such a rate limiter. Consider the following: How would you store the rate limit counters for each user or endpoint? What algorithm would you use to determine whether a request should be allowed or throttled? How would you handle distributed rate limiting across multiple servers? How would you ensure the rate limiter is resilient to failures? As an example, imagine a scenario where a social media platform wants to prevent users from spamming their API with excessive requests to post updates. The platform has millions of users and thousands of API endpoints. Some users pay for premium access with higher request limits. How would you design a robust and efficient rate limiter to handle this scale and these varying requirements?

Google

Tell me about the most challenging project you have ever handled. To provide more context, please consider the following aspects in your response: Describe the project briefly: What were the project's goals, and what was your role? What made it challenging? Was it a technical hurdle, a difficult deadline, a complex team dynamic, ambiguous requirements, or something else? Provide specific examples of the challenges you faced. How did you overcome these challenges? What steps did you take to address the issues? What resources did you utilize? Did you have to learn new skills or technologies on the fly? What was the outcome? Were you able to successfully complete the project? If not, what were the lessons learned? What would you do differently next time? What was your biggest takeaway from the project? How did this experience shape your approach to future projects? Did it change your perspective on teamwork, problem-solving, or project management? For instance, perhaps you led a project to migrate a legacy system to a new cloud-based platform, and you encountered unexpected compatibility issues that required you to develop innovative workarounds. Or maybe you were part of a team that was tasked with developing a new feature for a popular product, but the requirements changed frequently, and the timeline was extremely tight. Sharing these types of details will help me understand the scope and complexity of the project and how you responded to the challenges involved.