Every system design decision is a tradeoff.

Choose strong consistency and you sacrifice availability. Optimize for reads and writes become expensive. Pick a simple architecture and you limit future scalability.

Interviewers do not expect you to design perfect systems. They want to see that you understand these fundamental tensions and can reason through them intelligently.

In this chapter, I'll cover the 12 most important tradeoffs you need to understand for system design interviews.

1. Consistency vs Availability (CAP Theorem)