coder000

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.

Two series, one clinic

The newest series takes an ER sketch all the way to a production schema. It continues the 2024 series that started this site's design writing, which turns a conversation with a doctor into that first ER diagram.

12 parts · ~74 min total · starts at Part 1

Database Design for Developers

Twelve hands-on parts from an ER sketch to a production schema, on SQL Server and PostgreSQL side by side: keys, relationships, column types, constraints, normalisation, naming, indexes, soft delete and history, migrations, and search. Every script was run on both engines; every output shown is real.
All 12 parts →Start with Part 1📥 The finished clinic schema for PostgreSQL (every part has its own script to download)📥 The finished clinic schema for SQL Server🧭 The series this one continues: Conversation to System Design📦 ClinicLive, the clinic whose tables start the series

Design-adjacent reading

Where the design mindset meets performance, storage choices and interview practice.