Most of the practice examples I have gone through had solutions that seem "complete" to be finished within 30 minutes. I have an onsite Amazon interview, and I seriously don't know what is expected from the OOD round. I heard that behavioral + LP questions are asked for first 10 ~ 15 minutes. If each round is around 45 to 50 minutes, this means that I only have 30 minutes to complete OOD question.

I'm preparing OOD from https://www.***/courses/***-the-object-oriented-design-interview, but following the guidelines in here makes it nearly impossible to finish within 30 minutes. The general guidelines provided here is:

1. List all the system requirements
2. Draw Use Case Diagram / UML Class Diagram
3. Draw Activity Diagram
4. Write Skeleton Code

Drawing UML class diagram alone took me at least 25 minutes. Is there any tips on how to nail a OOD interview?