System design, from first principles
Great systems start long before the first line of code — in conversations, entities and relationships. This is coder000's founding topic: design explained so clearly that a beginner can follow, and practiced on real scenarios.
Conversation to System Design
From a doctor's chat to a complete database design
A seven-part, beginner-first series that takes one real conversation with a doctor and turns it into a complete database design — entities, attributes, relationships, keys and all.
Start with Part 1Design-adjacent reading
Where the design mindset meets performance, storage choices and interview practice.
Database Indexes: Why Your Queries Are Slow
The difference between scanning a million rows and jumping straight to one. How indexes work, when to add them, and the trade-offs nobody mentions.SQL vs NoSQL: Which Database Should You Learn First?
Tables or documents? Rows or JSON? What each kind of database is good at, where each struggles, and a clear recommendation for your first one.More is coming
System design is this site's home turf, and the roadmap here is long — deeper dives into scaling, architecture and real-world trade-offs are planned. Want a specific topic covered sooner? Tell us — suggestions regularly become tutorials.