There is no "perfect" system

There is no single design for any system that works perfectly. There are always trade-offs. Two different people can come up with different designs, with both being excellent given different assumptions.

Your goal is to:

1. Understand the use case
2. Scope the problem you are solving
3. Make reasonable assumptions
4. Create a solid design based on those assumptions
5. Be open about the trade-offs you made and the weaknesses of your design