Senior Software Engineer, Infrastructure, Platforms Infrastructure Engineering

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 system for URL shortening, like TinyURL. Assume that we need to handle a large number of requests, say billions of URLs per day. Consider the following: Functional Requirements: The system should generate a shorter, unique alias for a given URL. Users should be able to enter a shortened URL and be redirected to the original URL. The shortened URLs should be relatively short. Non-Functional Requirements: The system should be highly available. URL redirection should be as fast as possible. The shortened URLs should be unique. The system should be scalable to handle a large number of URLs and requests. Considerations: How would you design the data model to store the mappings between shortened and original URLs? What algorithms would you use to generate the shortened URLs? Consider the trade-offs between different algorithms. How would you handle collisions (when the same shortened URL is generated for two different original URLs)? What kind of database would you use and why? How would you handle the high volume of traffic and ensure low latency for redirection? Consider caching strategies. How would you scale the system to handle future growth? Walk me through your design, explaining your choices and the rationale behind them. Include diagrams and specific technologies where appropriate. Explain how you would ensure the system meets the requirements for availability, performance, and scalability.

Google

Where do you see yourself in 5 years?