Senior Systems Engineer, Site Reliability Engineering

Google

Let's explore some string manipulation algorithms. Suppose you are given a string s and you need to reverse the order of words in the string. Each word is separated by a single space, and there are no leading or trailing spaces. For example, if the input string s is the sky is blue, the expected output is blue is sky the. Write a function that takes a string s as input and returns a new string with the words in reversed order. Explain your approach. What is the time and space complexity of your algorithm? Provide example test cases to demonstrate that your function works correctly, including edge cases such as an empty string or a string with only one word. As a follow-up, consider a more complex scenario where the input string s might contain leading or trailing spaces, or multiple spaces between words. How would you modify your algorithm to handle these cases while still producing the correct reversed word order? For instance, given the input hello world , the output should be world hello. Describe the changes needed and analyze the updated time and space complexity.

Google

Let's design a web proxy. Consider the following requirements: Basic Functionality: The proxy should be able to forward HTTP and HTTPS requests from clients to web servers and return the responses. Caching: Implement caching to reduce latency and bandwidth usage for frequently accessed resources. How would you handle cache invalidation? Security: The proxy should support HTTPS and protect client data. How would you handle SSL/TLS certificates? Scalability: The proxy should be able to handle a large number of concurrent connections. What architectural choices would you make to ensure scalability? Authentication: Implement basic authentication (username/password) to control access to certain websites. Logging: Log requests and responses for debugging and monitoring purposes. What information should be logged, and how would you manage log files? Blocking: Implement the functionality to block access to certain websites based on a blacklist. Discuss the architecture, components, and algorithms involved in building such a web proxy. Include considerations for performance, security, and maintainability. Provide example scenarios and solutions to potential challenges.

Google

Tell me about a time you faced a significant challenge and how you overcame it. To provide a detailed response, please consider the following: Describe the challenge:** What specific obstacles did you encounter? What made it difficult to handle? Explain your actions:** What steps did you take to address the challenge? What resources did you utilize? Did you seek help from others? Highlight your thought process:** What were your considerations when deciding on a course of action? What alternatives did you consider, and why did you choose your particular approach? Detail the outcome:** What was the result of your efforts? Did you successfully overcome the challenge? If so, what did you learn from the experience? If not, what would you do differently next time? For example, perhaps you were working on a complex software project with a tight deadline and encountered unexpected technical difficulties. Or, maybe you had to mediate a conflict between team members with differing opinions on how to approach a problem. Another example could involve learning a new programming language or technology in a short timeframe to meet a critical project requirement. When answering, be sure to provide enough context so the interviewer understands the situation and can assess your problem-solving skills, resilience, and ability to learn from challenges.