Core Concepts: Complete Topic Index
Nine explanatory chapters are available as continuous reading. All prose is visible without expansion controls, quizzes, or self-checks. Each chapter connects concepts, mechanisms, suitable uses, and trade-offs through concrete examples.
| Chapter | Coverage |
|---|---|
| Networking | Request paths, layers, protocols, real-time communication, balancing, regions, and recovery. |
| API design | Contracts, asynchronous operations, idempotency, pagination, authorization, and evolution. |
| Data modeling | Access patterns, entities, constraints, concurrency, object storage, and lifecycle. |
| Indexes | Pages, B-trees, LSM, composite and covering indexes, plans, and maintenance. |
| Caching | Placement, access patterns, freshness, invalidation races, hotspots, and origin protection. |
| Sharding | Keys, placement, hotspots, cross-shard operations, and migration. |
| Consistent hashing | Remapping, rings, virtual nodes, membership versions, and replication boundaries. |
| CAP and consistency | Partition behavior, consistency models, and end-to-end read guarantees. |
| Capacity estimates | Demand, storage, bandwidth, concurrency, resources, queues, and headroom. |
Reading order
Networking and APIs → modeling and indexes → caching → sharding and consistent hashing → CAP → estimation. Start with one request, then consider scaling and failure. Individual chapters can also be opened directly.
Diagrams and offline reading
Each chapter includes an SVG preview. Download the interactive system-design overview, Chinese as standalone HTML. The complete pack contains both languages, diagrams, and an Obsidian-ready folder.
Reading references
All nine written topics were reviewed through the existing authenticated Hello Interview session. These guides are independently organized around system questions with primary documentation and worked examples; they do not transcribe course videos or quizzes. Other patterns, technologies, and design problems are outside this set.