Agile on the Beach on YouTube · Open on YouTube
System design and architecture · Proficient · Lesson 66 of 98 · 36 min video, then about 2 hours of practice
Communicating architecture with diagrams
After this you can draw C4 context, container and component diagrams that someone new to the system can understand without you in the room.
Why it matters
Most architecture diagrams are boxes and arrows with no legend, mixing levels of detail. The C4 model gives you four zoom levels (context, containers, components, code) and simple rules: every box has a name, a type and a responsibility; every arrow says what it carries. Draw the context and container diagrams for a system you work on. You will discover things nobody on the team agreed on. Trap: one giant diagram with everything on it. Different audiences need different zoom levels.
How to use this resource
The creator of C4 explaining why most diagrams fail and how to fix them.