How to do System Design

Step 1: System Clarify
(UDF)
User: who is the user? how does the user use the system? frequency? expected results? malicious?
Data: what data content? what format? size? redundancy?
Function: Insert? Delete? Query? Scale? Major limitations?

Step 2: Concept Design
Components (or Modules)
Entities (or Classes)
Interactions (or Interfaces)

Step 3: Design
Data Structures
Algorithms
Database Schema (Key and Index)
Class Diagram

Step 4: Analysis
Complexity Analysis (Time & Space)
Scalability Analysis
Memory Limitation
Flexibility or Extensions