> For the complete documentation index, see [llms.txt](https://book.aonecode.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://book.aonecode.com/system-design-pro.md).

# System Design Pro

- [Essential System Design: 10 Key Questions and Answers on CDNs](https://book.aonecode.com/system-design-pro/essential-system-design-10-key-questions-and-answers-on-cdns.md)
- [Quickly Comprehend Persistent Connections And The Heartbeat Mechanism](https://book.aonecode.com/system-design-pro/quickly-comprehend-persistent-connections-and-the-heartbeat-mechanism.md): Quickly Comprehend Persistent Connections and the Heartbeat Mechanism
- [Must-Know System Design Tips](https://book.aonecode.com/system-design-pro/must-know-system-design-tips.md): A system design interview guide from entry-level to senior