Principal Architect III, HPC, Google Public Sector

Google

Let's simulate a coding interview scenario. I'd like you to solve a problem and articulate your thought process as you go. Imagine you're given an array of integers. Your task is to write a function that finds the length of the longest strictly increasing subsequence in that array. A strictly increasing subsequence is a sequence of numbers from the array such that each number is greater than the previous one, and their original order in the array is maintained. For example, in the array [1, 3, 2, 4, 5], one possible increasing subsequence is [1, 2, 4, 5], and the longest increasing subsequence is [1, 2, 4, 5], which has a length of 4. Another possible increasing subsequence is [1, 3, 4, 5] which has length of 4. Your function should return 4 in this case. Another example is [10, 9, 2, 5, 3, 7, 101, 18]. The longest increasing subsequence is [2, 3, 7, 18], which has a length of 4. Your function should return 4. Can you describe your approach and then implement the function? Consider edge cases, like an empty array or an array with only one element. How would your approach handle those? What is the time and space complexity of your solution?

Google

Let's design a cache. Consider the following requirements: Basic Functionality: Implement a cache with put(key, value) and get(key) methods. Eviction Policy: Implement an LRU (Least Recently Used) eviction policy. When the cache is full, the least recently accessed item should be evicted to make space for the new item. Thread Safety: Ensure the cache is thread-safe to handle concurrent access from multiple threads. Generics: The cache should be able to store any type of key and value (using generics). Time Complexity: get and put operations should have an average time complexity of O(1). Example Usage: Cache cache = new Cache(5); // Cache with capacity 5 cache.put(1, one); cache.put(2, two); cache.get(1); // Access key 1, moves it to the most recently used cache.put(3, three); cache.put(4, four); cache.put(5, five); cache.put(6, six); // This will evict key 2 (LRU) System.out.println(cache.get(2)); // Output: null (because it was evicted) Discuss the data structures you would use, the implementation details for each method, and how you would address thread safety.

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.