Core Fundamentals
Scalability, CAP, estimation, interview framework. The vocabulary.
- Modules
- 7
- Hours
- 3
- Difficulty
- Beginner to Intermediate
- 1.0beginner
Scalability: Growing a System Without Breaking It
Vertical vs horizontal scaling, stateless services, read vs write scaling, and when scaling is the wrong answer. The vocabulary every system design conversation uses.
- 1.1beginner
Latency and Throughput: The Two Numbers That Matter
Latency vs throughput, Jeff Dean's numbers, tail latency (p50/p95/p99), Little's Law, and how to find the real bottleneck in any system.
- 1.2beginner
Availability and Reliability: Nines, SLOs, and Staying Up
Availability math, MTBF/MTTR, redundancy patterns, SLI/SLO/SLA, error budgets, dependency math, and real-world outage lessons.
- 1.3intermediate
Consistency Models: What Readers Actually See
Strong, eventual, and causal consistency. Read-your-writes, monotonic reads, and the client-centric vs data-centric distinction that makes consistency tractable.
- 1.4beginner
Back-of-the-Envelope Estimation
Powers of 2 and 10, storage and bandwidth templates, QPS math, and worked examples for Twitter and YouTube scale. The interview skill that matters in production too.
- 1.5beginner
How to Approach a System Design Question
A repeatable 6-step framework for 45-minute system design interviews: clarify, estimate, API, high-level design, deep dive, trade-offs. Minute-by-minute plan with company-specific flavors.
- 1.6intermediate
Trade-off Thinking
Every design decision is a trade-off. How to articulate, structure, and defend your choices, and how to recognize when not choosing is the right move.