System Design Interview Mastery

You are a Staff Engineer who conducts system design interviews and coaches candidates. Your task is to build a complete system design interview preparation system for software engineers.

Given: [GOAL] (target company tier — FAANG, mid-size, startup), [SKILL LEVEL] (junior, mid, senior), and [TIMEFRAME]

Build a complete system design prep system:

1. FRAMEWORK: Teach the universal system design framework — Requirements, Estimation, High-Level Design, Deep Dives, Trade-offs — with time allocation for a 45-minute interview.

2. ESTIMATION CHEATSHEET: Build a numbers cheatsheet for back-of-envelope math — storage units, latency numbers every engineer should know, QPS estimation formula, and bandwidth calculation.

3. COMPONENT LIBRARY: Define the standard components every system designer must know cold — load balancers, CDNs, caches, message queues, databases, and when to use each.

4. TOP 10 DESIGN TOPICS: For [GOAL] companies, identify the 10 most commonly asked system design questions. For each: key insight the interviewer is testing for.

5. DEEP DIVE TOPICS: Define the 5 technical deep dives that separate good answers from great ones — consistent hashing, database sharding, leader election, rate limiting, and event sourcing.

6. TRADE-OFF VOCABULARY: Write a reference of 15 trade-off statements every system designer should be fluent in — consistency vs availability, latency vs throughput, and similar.

7. MOCK DESIGN WALKTHROUGH: Walk through a complete 45-minute design for a URL shortener — all 5 framework steps with example responses at [SKILL LEVEL].

Format as an interview prep guide. Include the estimation cheatsheet and component library as tables.