1.Remove duplicate from array while maintaining the order 2. Morris Traversal on BST .

“Design a customer support ticketing system.” This usually appears in the system design round and involves: • Defining API endpoints for creating, updating, and retrieving tickets. • Designing the database schema (e.g., tables for tickets, users, status, comments). • Explaining scalability (handling thousands of tickets per second). • Considering search (filter by status, priority, assignee). • Adding features like real-time notifications and priority escalation. Another one that pops up in multiple experiences is: “Write a SQL query to find the top N customers by revenue.”