Data Structures & Algorithms: Implement a linked list, binary tree, or graph. Find the longest substring without repeating characters. Merge k sorted lists. Design a cache (LRU Cache). System Design: Design a URL shortening service like bit.ly. Design a scalable notification system. Design a distributed file storage system like Google Drive. Behavioral: Tell me about a time you faced a significant challenge at work. How do you prioritize tasks when managing multiple projects? Describe a situation where you had to resolve a conflict within a team.