Staff Research Scientist, Google Cloud AI

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 prototype for a system that answers questions based on financial documents. To make this concrete, imagine a user needs to quickly find information within a company's annual report (a PDF containing financial statements, management discussion, etc.). The user might ask questions like: What was the company's revenue for the last fiscal year? What were the primary risks identified by management? How did operating expenses change compared to the previous year? Describe your approach to building a prototype that can accurately and efficiently answer these types of questions. Consider aspects such as: Document ingestion and processing:** How would you load and pre-process the financial documents (e.g., PDF parsing, text extraction)? Information retrieval:** What techniques would you use to identify the relevant sections of the document that contain the answer? Question answering:** How would you extract the answer from the relevant text (e.g., using rule-based methods, machine learning models)? Data storage:** How would you store the information from the documents to allow for efficient querying? User interface:** How would the user interact with the system to ask questions and receive answers? Evaluation:** How would you evaluate the performance of your prototype?

Google

Describe a time you faced a tough technical problem. What made it so difficult, and how did you approach solving it? What resources did you consult, and what was the final outcome? What did you learn from this experience, and how has it shaped your problem-solving skills since then? For example, perhaps you were tasked with optimizing a slow-running query in a large database. The initial attempts to improve performance, such as adding indexes, didn't yield the desired results. You then had to dive deep into the query execution plan, identify bottlenecks, and rewrite the query using more efficient techniques, like leveraging window functions or temporary tables. You could also describe the challenges faced while integrating a new feature into a legacy system with poorly documented code. You might have had to reverse engineer parts of the system, deal with unexpected dependencies, and carefully test the integration to avoid breaking existing functionality. Elaborate on the specific tools and methodologies you employed during these challenges, such as debuggers, profilers, or version control systems. Also, explain how you collaborated with team members or sought assistance from external resources like online forums or documentation to overcome the obstacles.