Senior Software Engineer, Full Stack, Commerce

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 simplified distributed key-value store. Assume we need to handle a high volume of read and write requests. The key-value store should support the following operations: get(key): Retrieves the value associated with the given key. put(key, value): Stores the value associated with the given key. Here are some specific considerations for the design: Scalability: The system should be able to scale horizontally to handle increasing amounts of data and traffic. Consider how data will be distributed across multiple servers. Consistency: Discuss the consistency model you would implement. Would you choose strong consistency or eventual consistency? What are the trade-offs? Provide a rationale for your choice. Elaborate on how your design ensures that reads return the most up-to-date data (or how it handles potential inconsistencies, if any). Fault Tolerance: How would the system handle server failures? Describe the mechanisms you would implement to ensure data durability and availability in the face of node failures. Explain the role of replication and how it impacts consistency. Data Partitioning: Describe your data partitioning strategy. Consider using techniques like consistent hashing or range-based partitioning. Explain how your chosen strategy affects load balancing and data locality. Provide a concrete example of how keys would be mapped to specific servers in your design. Caching: Where would you incorporate caching in your system to improve read performance? Discuss different caching strategies (e.g., client-side caching, server-side caching) and their implications. Walk me through the architectural components of your key-value store, including the roles of different servers, the communication protocols used, and the data flow for get and put operations. Explain any potential bottlenecks and how you would address them. For example, if consistent hashing is used, how do you handle nodes being added or removed from the cluster?

Google

Okay, let's delve into your motivations. Why are you interested in working at this company specifically? I'm looking for more than just a generic answer about seeking a new job. I want to understand what resonates with you about our company's mission, values, and the specific role you're applying for. To give you some context, consider our commitment to innovation in the field of AI, particularly our recent work on developing more ethical and transparent algorithms. Or perhaps you're drawn to our collaborative work environment, where cross-functional teams work together to solve complex problems. Maybe you admire our company's dedication to social responsibility, like our initiatives to promote STEM education in underserved communities. When answering, please be specific and show that you've done your research. For instance, you could discuss a particular project that caught your attention, how your skills and experience align with the team's needs, or how you see yourself contributing to our company's long-term goals. Avoid vague statements like I'm a hard worker or I'm a team player without providing concrete examples. Instead, focus on demonstrating a genuine interest in our company and a clear understanding of how you can make a valuable contribution. To summarize, I want to know: What specifically attracts you to our company? How do your skills and experiences align with the requirements of this role and the company's goals? What unique contributions do you believe you can make to our team and our overall mission?