Senior Software Engineer - AdTech

Uber

Given a number, find the next highest number that is a palindrome. For example: If the given number is 123, the next palindrome is 131. If the given number is 99, the next palindrome is 101. If the given number is 1221, the next palindrome is 1221 (as it is already a palindrome). If the given number is 899, the next palindrome is 909. If the given number is 999, the next palindrome is 1001. Your task is to write a function that takes an integer as input and returns the next palindrome number. The palindrome must be strictly greater than the input number. Consider edge cases, such as when the input number consists of all 9s. What is the most efficient approach to solve this problem, and what is its time complexity?

Uber

System Design: Google Calendar Let's design a system similar to Google Calendar. Consider the following requirements: Functionality: Users should be able to create, read, update, and delete (CRUD) events. Events should have a title, description, start time, end time, location, and attendees. Recurring Events: Support recurring events (e.g., daily, weekly, monthly) with options for specifying exceptions (e.g., skip a specific instance). Invitations and Notifications: Users should be able to invite other users to events. Invited users should receive notifications about new events, updates, and cancellations. Implement a notification system, detailing frequency and method (e.g., email, push notification). Reminders: Users should be able to set reminders for events (e.g., 10 minutes before, 1 hour before). Time Zones: The system must correctly handle events across different time zones. Availability: Users should be able to view the availability of other users when scheduling events (free/busy). Scalability: The system should be able to handle a large number of users and events, ensuring responsiveness and reliability. How would you scale the system to accommodate millions of users and concurrent events? Consistency: Ensure data consistency across different users' views of the same event. Conflict Resolution: Address how to handle conflicting events and notify users accordingly. Specifically address these points in your design: Data model: How would you represent events, users, and their relationships in a database? API design: What API endpoints would you provide for creating, reading, updating, and deleting events? Concurrency and locking: How would you handle concurrent access to events to prevent data corruption? Notification system: How would you implement the notification system for event invitations, updates, and reminders? Scalability strategies: What strategies would you use to scale the system to handle a large number of users and events? Conflict Detection: How will the system determine event conflicts, and what notification mechanisms will be in place?

Uber

Describe a time you disagreed with your team members.