The Building Blocks Framework

A free 7-lesson video series teaching you how to design any software system using seven universal building blocks and three external forces.

This is the original free version. Course I rebuilds the same framework with hands-on labs, an AI-graded assessment, and a 3-part design challenge. See Course I →
Lesson 1

Why System Design Feels Impossible for Junior Engineers

Most junior engineers can write code. Few can confidently sketch how a real system fits together. The skill that separates the two is called system...

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Lesson 2

0s & 1s Run Everything

Every system you have ever used — Instagram, your bank, the device you are reading this on — eventually resolves to the same two characters: zero and one....

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Lesson 3

How Storage Actually Works

Storage is one of the two halves of computing, and it is where most system designs either click or fall apart. Storage is just zeros and ones arranged in...

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Lesson 4

Now or Later? The Two Task Types

Tasks are the other half of computing — the part that takes inputs and produces outputs by following instructions. Every line of code you have ever...

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Lesson 5

The 7 Building Blocks Behind Every System

This is the keystone lesson. Up to this point Kay has built the foundation: bits, storage, tasks. Now he assembles them into the seven building blocks...

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Lesson 6

How Seniors Think About System Design

Senior engineers do not have a secret framework you have never seen. They have the same building blocks every other engineer has access to. What separates...

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Lesson 7

Putting It All Together: A Fundamental Approach to System Design

The final lesson of the free series is the bridge from framework to practice. Kay walks through the full arc of the course — bits to storage to tasks to...

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