Step 2: Break It Down Into Components

Someone says "Design Facebook" and your mind goes blank. Here's the secret: nobody designs Facebook all at once.

Instead, think about what Facebook actually does:

• Authentication: Users need to log in
• Feed: Users need to see posts
• Notifications: Users need to be alerted
• Messaging: Users need to communicate
• Posts: Users need to create content

Sudenly, "Design Facebook" becomes "Design 5 separate systems that work together."

Each component should be:

• Mutually exclusive: Clear boundaries between components
• Independently designable: You can work on one without others
• Microservice-ready: Big enough to be its own service

Now instead of one impossible problem, you have multiple solvable problems!

Key Insight: "The art of system design is knowing where to draw the lines between components."