Observe the world
System design sparring
Prompts you copy and take elsewhere. Paste one into any large model and it plays the interviewer, asking you through the problem scene by scene rather than reciting the answer.
These prompts only exist in 简体中文 for now.
How to use this
How to start
- Pick a question, open it, copy the prompt.
- Paste it into a brand-new conversation — not one where you already discussed this question, or the model follows your old answers.
- Say nothing. Wait for its first question.
Four commands you can call out at any time
跳过move to the next scene now提示give a direction, not the answer直说吧spell this point out in full, then keep pressing on the trade-offs复盘jump to the wrap-up and print the review card
Three traps
- Don't do two questions in one conversation — context from the first makes the model prejudge your level.
- Don't look up the answer the moment it asks. Being stuck for 30 seconds is itself useful information.
- When it starts praising you, point it back to rule five — feeling validated crowds out noticing what you missed.
Suggested order: start with the cross-cutting drill as a parts test, use the short-link question to get used to the flow, then pick by the direction you interview for, and keep redoing the one about your own project.
Frequently asked
短链系统
最简单的一道，专门考基本功。
Feed 流 / 朋友圈 / 微博时间线
读扩散还是写扩散，以及那个有一千万粉丝的人。
排行榜 / 计数系统
ZSet 谁都会用，同分怎么排、亿级怎么算名次就不一定了。
限流器
四种算法的临界问题，以及计数的那台 Redis 挂了你放还是不放。
大文件上传 / 网盘
分片、续传、秒传，以及回调凭什么可信。