Software Engineer II, Backend - Delivery Platform

Uber

Given a list of strings, determine the lexicographical order of the alphabet used in those strings. Assume the strings are sorted lexicographically based on this unknown alphabet. For example, if the input list is [baa, abcd, abca, cab, cad], the function should return the order ['b', 'd', 'a', 'c']. Another example would be if the input list is [caa, aaa, aab], then the correct ordering would be ['c', 'a', 'b']. Note that not all letters from the standard alphabet have to be present, and the input list might not explicitly define the relationship between all letters. Can you implement an algorithm to derive this alphabetical order?

Uber

Let's design a room reservation system. Consider the following requirements: Users: The system should allow users to search for available rooms and make reservations. Rooms: Each room has a capacity, a list of available equipment (e.g., projector, whiteboard), and a location. Reservations: Reservations have a start time, an end time, a room, and a user. Conflicts: The system must prevent double-booking of rooms. If someone tries to book a room that is already booked during that timeframe, they should receive an error message. Searching: Users should be able to search for rooms based on criteria such as capacity, available equipment, location, and time slot. Admin: Admins should be able to add new rooms, modify room details, and view all reservations. Consider the data models, APIs, and system architecture. Provide a high-level overview of your design, including the key components and their interactions. What data structures would you use to efficiently store and retrieve room and reservation information? How would you handle concurrency and prevent race conditions when multiple users try to book the same room simultaneously? What are the trade-offs between different architectural choices (e.g., monolithic vs. microservices)? What API endpoints would you expose for common operations like searching for rooms, creating reservations, and canceling reservations? How would you handle edge cases such as overlapping reservations or invalid user input? What database technology would you use and why?

Uber

Tell me about yourself and describe your past experiences in detail, focusing on specific accomplishments and challenges you faced.