Firmware Technical Lead

Google

You are given a singly linked list. How do you traverse it in reverse order using O(1) memory? For example, given the list 1 -> 2 -> 3 -> 4 -> null, your traversal should output 4, 3, 2, 1. Explain your approach and provide a code example. Consider the constraints of not modifying the linked list structure itself. Can you adapt your approach if modifying the list structure is permitted, and what would be the trade-offs?

Google

Let's design a rate limiter. This is a crucial component in many systems to prevent abuse and ensure fair usage. Your rate limiter should meet these requirements: Functionality: It should limit the number of requests a user can make within a specific time window. For example, allow a user to make 10 requests per minute. Scalability: The rate limiter needs to handle a large number of users and requests concurrently. Imagine millions of users accessing the system. Accuracy: It should accurately track and enforce the rate limits. A small degree of error is acceptable, but significant deviations are not. Low Latency: The rate limiter must not introduce significant delays in request processing. The overhead should be minimal. Fault Tolerance: The system should continue to function correctly even if some components fail. It should be resilient to outages. Cost-Effectiveness: The solution should be cost-effective in terms of resources used (e.g., memory, CPU, network bandwidth). Consider these scenarios and constraints: Users are identified by a unique ID. The time window is configurable (e.g., seconds, minutes, hours). The rate limit is also configurable per user or group of users. You can use any data structures and algorithms you deem appropriate. Assume you have access to a distributed cache (e.g., Redis, Memcached). Walk me through your design. Discuss different approaches, their trade-offs, and how you would address the requirements. Specifically, consider the following: Data structures for storing request counts. Algorithms for incrementing and checking request counts. Handling concurrency and race conditions. Strategies for distributing the rate limiter across multiple servers. How to handle exceeding the rate limit (e.g., returning an error code). Monitoring and alerting. For example, if a user with ID user123 tries to make 11 requests within a minute when their limit is 10, the rate limiter should reject the 11th request. How would your system achieve this efficiently and reliably at scale?

Google

Let's discuss your skillset. To start, can you elaborate on your technical proficiencies, such as your experience with programming languages, frameworks, and tools? For instance, have you worked with Python, Java, or C++? Are you familiar with front-end frameworks like React or Angular, or back-end technologies like Node.js or Django? Can you provide examples of projects where you effectively utilized these skills to overcome technical challenges? Furthermore, how do you approach learning new technologies and integrating them into your existing workflow? In addition to technical skills, can you share examples of your soft skills, such as communication, teamwork, problem-solving, and leadership? For example, describe a situation where you effectively communicated a complex technical concept to a non-technical audience, or a time when you successfully collaborated with a team to achieve a common goal. How do you handle conflicts within a team, and what strategies do you employ to ensure that everyone's voice is heard? Finally, how do you stay up-to-date with the latest industry trends and advancements, and how do you continuously develop your skills to remain competitive in the ever-evolving tech landscape?