1. You are given a very large file which contains numbers on each line. You are asked to sort them. Constraints are such that you cannot load the entire file into memory.
2. You're given 2 numbers a and b. The goal is for you to reach from a to b in minimum number of steps possible when a = b. You can do a set of 4 things - divide a by 7 if it's a multiple of 7, divide a by 3 if it's a multiple of 3, decrease a by 1 or increase a by 1.
3. System Design - Graph Traversal problem (not as traditional as other infra based system design)
4. Behavioral

Good luck!