Firmware Technical Lead

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 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 a time you had to sign a non-disclosure agreement (NDA). What were the key terms, and how did you ensure compliance while working on the project? Consider these points in your answer: Context: Briefly describe the project and the purpose of the NDA. Who were the parties involved, and what information was being protected? Key Terms: What were the most important clauses or restrictions outlined in the NDA? This could include limitations on sharing information, reverse engineering, or using the protected information for purposes outside the scope of the agreement. Compliance Measures: What specific steps did you take to ensure you and your team complied with the NDA? Did you implement any specific procedures, such as data encryption, access controls, or regular training? Challenges: Did you face any challenges in adhering to the NDA? If so, how did you overcome them? Did you need to seek clarification on any terms or consult with legal counsel? Outcome: What was the result of the project, and how did the NDA contribute to its success? Did the NDA effectively protect the confidential information, and were there any lessons learned from the experience? For example, perhaps you worked on a project involving a new algorithm for a company. The NDA might have restricted you from sharing the algorithm with anyone outside the project team, reverse engineering it, or using it for any other projects. You might have implemented access controls to limit who could access the algorithm's source code and conducted regular training sessions to remind the team of their obligations under the NDA. You should talk about how you proactively avoided violations and made sure your actions were fully within the legal scope of the agreement.